CRJ 311 Ashford University The Science of Evidence Essay

Week 4 – AssignmentThe Science of Evidence
[WLOs: 1, 2, 3, 4] [CLOs: 2, 4, 5]
Last week, you evaluated on-scene analysis and documentation. This week, the focus will shift to the scientific
processes accomplished within the crime laboratory. In addition to the scientific processes, it is important to
understand the standards applied to determine if the scientific process and its results can or should be admitted
at trial. While science uses the peer review process to evaluate credibility, the courts also use case law to
evaluate the standards for forensic science.
Prior to beginning work on this assignment, please review the following:
• From the text:
◦ Chapter 5: Forensic Toxicology
◦ Chapter10: Blood and Other Biological Fluids
◦ Chapter 11: DNA Analysis
• The articles:
◦ Surrogate Testimony After Williams: A New Answer to the Question of Who May Testify Regarding
the Contents of a Laboratory Report
◦ What Happens If Autopsy Reports Are Found Testimonial?: The Next Steps to Ensure the
Admissibility of These Critical Documents in Criminal Trials
◦ To Analyse a Trace or Not? Evaluating the Decision-Making Process in the Criminal Investigation
◦ Examining the Role of Science in the Courtroom: Admissibility and Reliability of Forensic Science
in the Courtroom
◦ Testing the Testimonial Doctrine: The impact of Melendez-Diaz v. Massachusetts on State-level
Criminal Prosecutions an Procedure
• The e-book Forensic Science Evidence: Can the Law Keep up with Science?
• From the video Forensic Science in Action: From Crime Scene to Courtroom: Segment 6. Forensics:
Examination of the Victim 03:25

0:00 / 2:05
• The video Duties of a Forensic Scientist in the Forensic Biology Lab shown above.
You must use at least three Scholarly, Peer-Reviewed, and Other Credible Sources
(https://content.bridgepointeducation.com/curriculum/file/e5359309-7d3c-4a21-a41044d59303ccef/1/Scholarly%20Peer-Reviewed%20and%20Other%20Credible%20Sources.pdf) in addition to the
course text.
You are also strongly encouraged to review the recommended sources, which may further support this
assignment.
In your paper, address the following:
• Evaluate the evolution of forensic science, focusing on the types of scientific analysis conducted in crime
laboratories.
• Explain how the changes in science and evidence processing over the last century have affected the criminal
justice system.
• Describe at least four major types of scientific testing conducted by crime laboratories.
• Describe the evidentiary value of the four major testing processes identified.
• Analyze the current standards (based on case law) for admitting scientific evidence at trial, specifically
addressing the four types of scientific testing identified in your paper.
The Science of Evidence paper
• Must be 750 words in length (not including title and references pages) and formatted according to APA style
as outlined in the Ashford Writing Center’s APA Style (http://writingcenter.ashford.edu/apa-style)
• Must include a separate title page with the following:
◦ Title of paper
◦ Student’s name
◦ Course name and number
◦ Instructor’s name
◦ Date submitted
For further assistance with the formatting and the title page, refer to APA Formatting for Word 2013
(http://writingcenter.ashford.edu/apa-formatting-word-2013) .
• Must utilize academic voice. See the Academic Voice
(http://writingcenter.ashford.edu/academic-voice)
resource for additional guidance.
• Must include an introduction and conclusion paragraph. Your introduction paragraph needs to end with a
clear thesis statement that indicates the purpose of your paper.
◦ For assistance on writing Introductions & Conclusions (http://writingcenter.ashford.edu/introductionsconclusions) as well as Writing a Thesis Statement (http://writingcenter.ashford.edu/writing-a-thesis) ,
refer to the Ashford Writing Center resources.
• Must use at least three scholarly, peer-reviewed, and/or credible sources in addition to the course text.
◦ The Scholarly, Peer-Reviewed, and Other Credible Sources
(https://content.bridgepointeducation.com/curriculum/file/e5359309-7d3c-4a21-a41044d59303ccef/1/Scholarly%20Peer-Reviewed%20and%20Other%20Credible%20Sources.pdf) table offers
additional guidance on appropriate source types. If you have questions about whether a specific source is
appropriate for this assignment, please contact your instructor. Your instructor has the final say about the
appropriateness of a specific source for a particular assignment.
◦ To assist you in completing the research required for this assignment, view this Ashford University
Library Quick ‘n’ Dirty
(https://ashford.mediaspace.kaltura.com/media/Ashford+University+Library+Quick+%27n%27+Dirty/0_bcsbcjee)
tutorial, which introduces the Ashford University Library and the research process, and provides some
library search tips.
• Must document any information used from sources in APA style as outlined in the Ashford Writing Center’s
Citing Within Your Paper (http://writingcenter.ashford.edu/citing-within-your-paper)
• Must include a separate references page that is formatted according to APA style as outlined in the Ashford
Writing Center. See the Formatting Your References List (http://writingcenter.ashford.edu/format-yourreference-list) resource in the Ashford Writing Center for specifications.
Consider using Q for your library research and to access writing supports, and tutoring services available to you.
See the Guide to Installing and Using Q
(https://content.bridgepointeducation.com/curriculum/file/dd00f7497449-469c-9bd3-1e6e269bd895/1/Guide%20to%20Installing%20and%20Using%20Q%20for%20Success.pdf) for more
information.
Carefully review the Grading Rubric (http://au.waypointoutcomes.com/assessment/25748/preview) for the
criteria that will be used to evaluate your assignment.
Waypoint Assignment
Submission
The assignments in this course will be submitted to Waypoint. Please refer to the instructions below to submit
your assignment.
1. Click on the Assignment Submission button below. The Waypoint “Student Dashboard” will open in a new
browser window.
2. Browse for your assignment.
3. Click Upload.
4. Confirm that your assignment was successfully submitted by viewing the appropriate week’s assignment tab
in Waypoint.
For more detailed instructions, refer to the Waypoint Tutorial
(https://content.bridgepointeducation.com/curriculum/file/dc358708-3d2b-41a6-a000ff53b3cc3794/1/Waypoint%20Tutorial.pdf)
(https://content.bridgepointeducation.com/curriculum/file/dc358708-
3d2b-41a6-a000-ff53b3cc3794/1/Waypoint%20Tutorial.pdf) .
This tool needs to be loaded in a new browser window
Load Week 4 – Assignment in a new window
Forensic Toxicology
5
Jochen Tack/imageBROKER/SuperStock
Learning Outcomes
After reading this chapter, you should be able to
• Describe the types of cases that toxicologists analyze.
• Identify different poisons and how they are sampled.
• Explain how of icers recognize drugs and alcohol in the ield and how they
obtain samples for the toxicologist.
• Discuss how toxicologists test blood and urine samples for drugs and alcohol.
• Describe the drugs used in drug­facilitated sexual assault and how they are
analyzed.
• Explain the purposes of forensic urine drug testing and how it is done.
Introduction
Poisons have been present throughout human history. Poisoning can be accidental. For instance, someone can eat the wrong plant, mushroom, or ish and die.
However, poisonings can also be planned. Poisons derived from plant extracts have been used in executions; Socrates suffered this fate. He was found guilty of
crimes against the state and was given a cup of hemlock to drink. In the past, if you wanted to kill an enemy, there were preparations available that could complete
the task. Today poisons are not used as often as instruments of homicide. However, methods of analysis have been found that can determine the presence of toxins
in the body and can assist the courts in determining if a person was indeed poisoned or under the in luence of a toxin or intoxicating compound.
In today’s world, we come in contact with tens of thousands of chemicals. Many are not harmful, but there are many others that are. We discussed drugs in
Chapter 4, so we are aware that drugs can cause death if taken in overdose quantities. In fact, nearly every drug can be fatal if enough is consumed. Essentially, this
makes almost every drug a poison. Even consumption of excessive water can deplete essential electrolytes in the body and cause death.
An interesting point can be derived from this knowledge: It is the dose that makes a poison. This means that if taken in small enough amounts, some poisons can
be used as drugs. This has been the case for many years. For example, arsenic was previously used to control rats and other vermin populations, but it was also
used at one time in some Chinese homeopathic medicines in very low doses. Anticancer drugs are poisons that are designed to kill many cancer cells while killing
relatively few healthy cells. Toxicology, therefore, is the study of drugs and poisons or toxins and the way they affect the body. It comprises knowledge from two
disciplines—pharmacodynamics, which studies the way drugs act on the body in both positive and negative ways, and pharmacokinetics, which studies how the
body acts on drugs. These disciplines and the information gained from the analysis of samples taken during investigations by law enforcement can be used in
court cases to help the trier of fact come to a conclusion about that case. This science is known as forensic toxicology.
5.1 Toxicology Cases
Forensic toxicologists always have a monumental task before them in inding toxic substances and poisons in the body, quantitating the level in the system, and
determining possible effects, such as the increasing amount of impairment as individuals consume more alcohol and raise their blood alcohol concentration
(BAC). The toxicologist will usually engage in analysis of two types of cases. The irst type involves poisonings, both accidental and intentional. The second type
involves people who use illicit drugs in a recreational manner or victims who have been given drugs without their knowledge. Those involve issues in which
humans are under the in luence of one or more compounds that impair their ability to perform tasks (human performance cases). Such cases are typical for the
forensic toxicologist and involve driving under the in luence of alcohol (DUI) or driving under the in luence of drugs (DUID). The toxicologist performs analyses
that can ind many more compounds than the drug chemist. A toxicologist also searches for compounds in blood, urine, or other biological samples, where the
concentration of compound present is in the parts per million range, and the interfering components in the sample can be in the hundreds. In comparison, a drug
chemist looks for a drug in a tablet, capsule, powder, or plant material, where the amount of drug is determined as a percentage of the total weight of the sample,
and there are relatively few interfering compounds or diluents. Another factor in a toxicologist’s work is metabolism. Metabolism is the body’s way of breaking
down a poison or drug into compounds called metabolites. Metabolites are compounds that can be eliminated from the body more ef iciently than the parent
compound (the poison or drug). In order to facilitate elimination, drugs are usually made more water soluble so they can be deposited in the urine. Once in the
urine, they can be eliminated from the body. There are other ways to get rid of a drug, but transforming it into a metabolite for removal is the most common. If
metabolism has progressed far enough, the original drug or toxin will not be found in the body. Instead, the analyst must search for one or more metabolites of the
drug. As we will see, all of these factors make forensic toxicology a very interesting job.
The majority of cases submitted for forensic toxicological analysis will include two classes of compounds. Those classes are (a) drugs of both the licit and illicit
kind and (b) volatile substances, such as ethanol and inhalants. Other toxins may be encountered, but to a much lesser extent. These include gases, metals,
pesticides, and other miscellaneous compounds. Cases and samples involving all of these compounds will make their way to a forensic toxicology laboratory from
a coroner’s of ice or medical examiner’s of ice and through law enforcement personnel.
There are also privately run laboratories that perform forensic toxicology testing in support of drug­use prohibitions, such as in certain occupations or in athletic
competitions. This aspect is discussed later in the chapter.
Think About It
While many forensic toxicology cases involve DUI and DUID—and these seem like pretty straightforward trials—forensic toxicologists spend a great deal of
time in court on these cases. Why do you think they are called to court so often?
5.2 Poisons
Historical poisons are encountered by the forensic toxicologist on a limited basis, but there are several types of poisons. Most will likely be seen in general
circumstances. Heavy metals, such as arsenic, mercury, and lead, are often encountered by people because of accidental ingestion. There have been cases of
homeowners removing lead­based paint with hair dryers without adequate ventilation; these people have come down with lead poisoning from inhaling the
fumes generated by the heat of the hair dryer. Children have succumbed to lead poisoning from eating chips of lead­based paint. Family members and their pets
have experienced arsenic poisoning after contact with older rat poisons. Other metals, such as thallium, cadmium, cobalt, and selenium, are included in this class,
though they are not often encountered or easily obtained and would most likely be involved in a case of intentional poisoning.
In these cases, blood and urine samples can be tested by the toxicologist. The principal test utilized is atomic absorption spectroscopy (AA), which is sensitive to
the µg/L level. Scientists measure everything in metric system units: “µ” means micro, or one millionth; “g” stands for grams. There are about 28 grams in an
ounce. “L” means liter, which is around a quart.
New testing methods have made it possible for other samples to be tested. Hair testing for some of the heavy metals, though not lead, can allow the toxicologist to
determine whether the dosing was acute, or one time only, or happened over a period of time, called chronic dosing. Analysis of tissue samples postmortem
would also be completed using AA, and it could be used to quantitate the level in the body to determine if it was metal poisoning that killed the victim.
Cases involving toxic substances have also been seen. For instance, in the early 2000s, ethylene glycol, a substance once commonly found in radiator luid, was
responsible for a large number of poisonings, some accidental and some not. The Georgia Poison Control Center, for instance, had 235 cases in 2004 (Morgan,
Geller, & Kazzi, 2011). The ethylene glycol is metabolized in the body to form a toxic substance that can be lethal. The ethylene glycol has been replaced in most of
these luids with propylene glycol to try and eliminate this type of poisoning, or in some cases a very bitter lavoring has been added to prevent accidental
ingestion. As of 2012 all producers of antifreeze for automobile use have either switched to propylene glycol or added the bitter lavoring agent. Interestingly,
there have been three recent murder mysteries in which the killer used ethylene glycol in radiator luid as the poison of choice.
Think About It
There is a wealth of knowledge communicated through the media and Internet, including information on the use of poisons. Do you feel that placing
information of this nature on television and the Internet allows people too much access to information that can prove to be harmful to people?
Recall from Chapter 1 that Mathieu Joseph Bonaventure Or ila is often called the father of forensic toxicology. In 1840 Dr. Or ila became involved in one of the most
famous (or infamous) cases of murder by poisoning in history, in which Marie Lafarge was convicted of poisoning her husband, Charles, with arsenic.
Case Illustration: Toxicology and Murder—in the Beginning: The Lafarges
Marie married Charles Lafarge in 1839. Although she did not come from an aristocratic background, she had been sent to the best schools and had moved
in the best circles. She agreed to marry Charles under the mistaken impression that he owned property and had a successful business. In fact, he was
marrying Marie for her dowry, to help pay down his debts.
They moved to a run­down house owned by Charles. She was quickly disillusioned about this arrangement and encouraged Charles to go to Paris to try to
raise money. While he was away in Paris, Marie sent him a Christmas cake. After eating a piece of it, he became violently ill. He discarded the remainder of
the cake, but did not think about seeing a doctor; he thought the cake had spoiled in transit. He still did not feel well after returning home. Marie prepared
his meals during this time, and he again fell ill. The family doctor thought the symptoms were “cholera­like” and was not suspicious when Marie asked him
for a prescription for arsenic to kill the rats that were disturbing Charles at night. Charles’s health deteriorated rapidly, and he eventually died. His family,
and others who had come to keep watch and help him, became suspicious of Marie. She had been observed stirring a white powder into food and drink
intended for Charles. A doctor that was consulted close to the time Charles died began to suspect poisoning, but it was too late.
One of Charles’s brothers, whose suspicions had been aroused, contacted the local police, and a magistrate came to do an inquiry. He took possession of
some food items that remained, which could contain a poison. He learned that Marie had purchased arsenic not long before Charles had received the cake
in Paris and again after he returned home. Marie’s gardener con irmed that she had given him arsenic to make a paste to kill rats. This paste was found
around the house, but it did not appear to have been disturbed by rats. The magistrate also asked Charles’s local doctors if they could perform a new test
for arsenic that he had heard about: the Marsh test. The doctors agreed but did not know about the test’s intricacies. They used older methods to test
Charles’s stomach contents taken at autopsy and obtained inconclusive results. Nevertheless, they reported arsenic present. One of the people tending to
Charles had taken Marie’s box, from which people had seen her taking the white powder for Charles’s food and drink, and it was turned over to the
magistrate. Arsenic was found in the box. In addition, the arsenic paste that had been placed in the house for the rat problem was found to be a mixture of
lour, water, and baking soda.
Marie was put on trial for murder. One of Marie’s lawyers knew Dr. Or ila. He submitted the local doctors’ arsenic testing results to Or ila and asked for an
opinion. Or ila submitted an af idavit to the trial court stating that the tests had been conducted poorly and that the result meant nothing. When the local
doctors testi ied about the arsenic in Charles’s body, the lawyer read Or ila’s af idavit informing the court about the Marsh test and insisted that he be
called to do the test and as a witness. Prosecutors were con ident of Marie’s guilt and said they would agree to the testing, but they did not see the necessity
of calling Or ila (who was the acknowledged expert on the Marsh test in Europe at the time). The judge agreed and ordered that local pharmacists conduct
the testing. They reported not inding any arsenic in the stomach contents taken at autopsy. Charles’s body was then exhumed and new specimens taken.
The pharmacists again failed to ind arsenic. Marie seemed to be vindicated.
However, the prosecutor learned from Or ila’s writings that arsenic can leave the stomach through normal digestive processes and thus not be present in
the contents. He also remembered the saved food items that Marie had given to Charles. He asked that they be tested. The defense, now con ident about
their case, agreed. This time, though, the pharmacists came back and said there was a large amount of arsenic in the food items. The prosecutor again asked
the judge to permit Or ila to come in and settle the matter, since there had been contradictory results. The defense more or less had to agree to this, having
consulted Or ila irst. Or ila conducted his tests in the presence of the pharmacists and found that arsenic was present in specimens taken from Charles’s
body. The defense team sought to call an opposing expert, François Raspail, who had opposed Or ila in court at other times. Unfortunately for Marie,
Raspail was late, and the trial ended. Marie was convicted and sentenced to life imprisonment. Suffering from tuberculosis, Marie was released in 1852 but
died the same year.
Re lect On It
In what ways do you think this case would be different today, in terms of determining the presence of arsenic in Charles’s body, the court proceedings, and
the verdict?
This was a spectacular case in the annals of criminal justice. People were divided on whether Marie was guilty. It was also one of the irst cases pitting experts
against one another in the courtroom—something that is quite common today.
Poisoning is now infrequent in murder cases. A couple of centuries ago, it was used often by the aristocracy to get rid of their enemies. A modern murder by
poison took place in 2000 in San Diego, California. This case is intriguing because it involves employees of the medical examiner’s forensic toxicology laboratory.
For more on this case, see the Case Illustration box later in this section.
Pesticides
Pesticides are not usually seen in forensic toxicology cases. A common class of pesticides is the organophosphates; these compounds include parathion and
diazinon. Most of these cases involve accidental exposures. Should a case be seen that is suspicious, blood and urine samples can be analyzed in the forensic
toxicology laboratory.
Chromatographic techniques can provide preliminary information about a sample through separation of the different components of a mixture. If you put a drop
of ink near the bottom of a piece of paper and then dip the paper in water, the water will be absorbed and travel up the paper. When the water hits the ink, some of
the pigments will continue upward with the water, while others remain behind. As the water continues to travel up the paper, you can see separation of the ink
pigments. This works the same way with forensic samples when put through instrumentation that is often used. By separating a mixture such as urine into its
individual components and comparing these to known pesticides, we can say that a pesticide could be present in the urine, and if so, it might be a particular
pesticide as opposed to many others.
Mass spectroscopy will then be used to conclusively identify the pesticide that was ingested by the victim and found in the urine. Remember from Chapter 4 that
mass spectroscopy can give molecular information that will allow the scientist to say without doubt that a particular pesticide, such as malathion, is present, as
opposed to any other pesticide that exists. Hospitals can determine this class of compound is involved based on symptoms, including salivation, lacrimation
(tears), excessive urination, diarrhea, nausea, and vomiting. Testing is then completed to determine if organophosphate class compounds are present. Should the
circumstances of the poisoning be suspicious, law enforcement will be called. Samples should be collected with proper chain of custody and sent to the forensic
science laboratory.
Carbon Monoxide
Carbon monoxide (CO) is encountered mainly in accidental deaths. This odorless, colorless gas binds to hemoglobin (the protein in red blood cells that carries
oxygen) so tightly that it cannot be easily displaced. As more and more hemoglobin is rendered useless by binding to CO, oxygen deprivation will set in and can
cause death. Most of the approximately 500 deaths from CO in the United States each year are due to malfunctioning lame heaters and a lack of CO detectors in
homes, and they are termed unintentional deaths (CDC, 2007). Suicide by CO poisoning using automobiles used to be common, though this is becoming less
popular as other methods of CO poisoning, such as by charcoal, have been found (Schmitt, Williams, Woodard, & Harruff, 2011). Carbon monoxide is formed when
organic fuels are burned with too little oxygen present to form carbon dioxide (CO2). Levels of less than 1.5% CO in the air can be lethal within minutes. In the lab,
a CO­oximeter will be used to measure the level of carboxyhemoglobin in the blood to determine if the cause of death was CO poisoning.
Other Gases
Toxicology laboratories are encountering other gases in samples from law enforcement agencies. Many of these submissions are due to intentional inhalation of
various substances for the purposes of getting high. Included in this group are the inhalants discussed in Chapter 4. These are the nitrites and nitrates; anesthetic
gases like nitrous oxide and halothane; and the luoro­ and chlorocarbon compounds, such as di luoroethane, found in of ice supplies and pressurizers for food
products. These compounds are easily purchased and abused. Users inhale the contents as they spray them from the can. The ingredients enter the bloodstream
very quickly through the lungs. The effects are similar to central nervous system depressants. An of icer on the scene may ind a user unresponsive, but he or she
will revive in minutes, and the compounds will clear from the bloodstream very quickly. Due to the rapid clearing of the compounds from the system, obtaining
samples for prosecution of cases is dif icult, since most of the drug will clear from the user’s system on the way to a collection site such as a hospital.
These compounds do not show up in Breathalyzer testing and will not be seen in the urine under normal testing, so a blood sample is best for cases involving
inhalants. In the laboratory, the sample will be tested using headspace gas chromatography with mass spectroscopy. This is the same technique used to ind
ethanol in the blood; it can easily differentiate and conclusively identify various inhalants for the courts.
Illicit Drugs and Medications
Illicit drugs and medications are commonly seen in toxicology cases. These also involve samples taken from living beings and samples taken postmortem. In the
case of drugs, testing will include the use of chromatography of various types, color tests, and immunoassay as the preliminary testing to determine the classes of
drugs that might be present. Extraction of the sample is completed to purify the sample. Final identi ication of the drugs is accomplished with mass spectroscopy
as the conclusive test. Blood and urine samples are the most common, though hair testing is on the rise. In postmortem cases, other samples will be collected,
including vitreous humor ( luid in the eye) and possibly tissue samples. While collecting luid from the eye may seem unusual or even disgusting, for the
toxicologist, the vitreous humor is a sample that is cleaner than samples like blood or even urine, because there are fewer bacteria and interfering compounds
contained in the luid. These samples will be collected by the medical examiner or forensic pathologist at autopsy.
The collection of gastric contents may seem like an obvious step from many of the forensic television shows, but the forensic toxicologist will not usually look for
the victim’s last meal. Instead, he or she will look for drugs or poisons that may have been used acutely to cause death. Sometimes, there will be the remnants of
tablets or capsules in the gastric sample. These are easily and quickly analyzed and can indicate what the toxicologist will ind in the blood. Additionally, gastric
contents can be analyzed to ind drugs of abuse that are not in standard dosage forms. For instance, GHB might be found in a victim who died shortly after
administration of the drug.
Multiple blood samples are often taken at autopsy because of a phenomenon called postmortem redistribution. This can be seen if the victim has been deceased
for a period of time, presenting the toxicologist with signi icant challenges. Drug concentrations in organs of the body will be higher than the blood concentration
until absorption and distribution take place. Upon death, this distribution cannot be completed. The drug will start diffusing through the body from the area of
highest concentration toward a lower concentration. What this means is that a blood sample taken from the chest area might have a very high concentration of a
drug, because of redistribution from the gastrointestinal tract into the bloodstream, while blood taken from the leg would have a lesser concentration.
Toxicologists must be able to analyze all presented samples to determine how much redistribution has taken place and what might have been an effective
concentration in the blood when the victim died.
The toxicologist will usually begin with a screening of the urine sample to ind out what classes of drugs could be present. The reason for starting with urine is
that after drugs are taken in to the body, they are distributed through the blood to the tissues. After the drug has acted on the body, it is metabolized and
eventually delivered to the kidneys to collect in the urine. Therefore, the urine will have a higher concentration of drug than the rest of the body. This makes
detection of drugs in urine much easier than in other body luids or tissues. Sampling for many immunoassay tests takes place directly on the urine with little or
no pretreatment. Immunoassay tests can simultaneously test for many classes of drugs, in very little time and with minimal sample use, allowing the toxicologist
to determine what classes of drugs could possibly be present in the individual. These tests rely on exposing a sample to reagents that react with drugs or the
metabolites of drugs that can be found in the urine after consumption of drugs. For instance, there is a reagent that, in the presence of benzoylecgonine, a
metabolite of cocaine, will give a reaction that can be read by the instrument. The analyst can then determine if the sample should be tested further to con irm the
presence of cocaine and its metabolites. There are many reagents that can test for a large variety of drugs of abuse. This testing is rapid and uses very little of the
sample.
At the same time the urine is screened for drugs, the blood can be tested for volatile substances such as ethanol, methanol, isopropanol, the inhaled gases, and
acetone. The test used for this analysis is called headspace gas chromatography. A sample of the blood is added to a vial with a compound called an internal
standard. This internal standard is a compound that behaves on the instrument very much like the compounds the toxicologist is analyzing. The internal standard
is not likely to be found in a sample, for a variety of reasons, including the fact that it might not give a reaction in the body, is not yet approved for use by the FDA,
or might act like the drug on the instrument while not actually being a drug. This compound helps standardize analysis so quantitation and identi ication can
easily be completed. The sample with the internal standard is sealed in its vial. The vial at this point is only partially illed, with signi icant air above the liquid.
This is the headspace. The vial is heated so a small amount of any volatile substance can evaporate into the air above the liquid. Each volatile substance has a
concentration that will evaporate into the headspace relative to the concentration left in the blood at the temperature used to heat the sample. After heating and
equilibration, a speci ic amount of the headspace is withdrawn from the vial and placed onto the gas chromatograph. All of the volatiles are separated in the gas
chromatograph and, after passing through a detector, are plotted on a graph. This graph will let the analyst determine the identity of the compound based on the
time it took to get through the column to the detector; it also allows the analyst to quantitate the amount based on the size of the peak.
After this analysis, other samples taken from the blood may be used to quantitate other drugs that may be present as indicated by the urine analysis. These tests
require extractions of the blood to clean up the sample for analysis, followed by instrumental analysis to identify and quantitate the amount of drug present in the
blood. Remember, only the drug in the blood has the ability to interact with tissues and let the drug have an effect.
Case Illustration:Toxicology and Murder—Modern Day: Rossum v. Patrick
Kristin Rossum was accused and convicted of poisoning her husband, Greg, using
fentanyl she had stolen from the medical examiner’s toxicology laboratory, where
she worked as a toxicologist. As you may recall from Chapter 4.4, fentanyl is a
synthetic narcotic analgesic, about 100 times more potent than morphine.
Kristin worked in the San Diego County Sheriff/Coroner Toxicology Laboratory. At
some point, she began an affair with Michael Robertson, the chief of toxicology,
who was also married at the time. Kristin was a drug abuser who stole drugs from
the workplace to feed her habit. Kristin’s husband learned about the affair and
threatened to expose her and her drug use if she did not quit her job.
On the day of Greg’s death, Kristin called 911. Responding paramedics found him
in the middle of the living room. His body had been sprinkled with red rose petals,
and a wedding picture had been placed nearby, a setting similar to a scene from
one of Kristin’s favorite movies. Kristin’s credit card had been used to buy a similar
rose. The paramedics took Greg to a hospital, where he was pronounced dead.
Police questioned Kristin weeks after Greg’s death. There was a con lict of interest
with the toxicology laboratory at her place of employment, so the toxicology
testing of specimens from Greg’s body was outsourced. The lab reported high
levels of fentanyl (above fatal levels) along with clonazepam and oxycodone at
therapeutic levels (both of these drugs are legal by prescription). The investigation
went on to uncover Kristin’s methamphetamine use and a large quantity of
fentanyl missing from the coroner’s of ice. Kristin was charged with and tried for
murder; the state’s allegation was that she killed Greg by administering to him a
fatal dose of fentanyl.
The evidence was circumstantial, but Kristin was convicted. The defense had
argued that Greg was suicidal and had poisoned himself. The jury did not agree.
Kristin was sentenced to life without the possibility of parole.
Kristin appealed for a new trial in federal court but was turned down. She then
appealed to the Ninth Circuit Court of Appeals. A three­judge panel of that court
was ready to reverse the lower court and grant her petition, but they withdrew
their opinion and replaced it with a one­paragraph statement that a newly decided
U.S. Supreme Court case, Harrington v. Richter (2011), controlled their decision.
Dennis Poroy/Associated Press
Kristin Rossum being escorted to the processing room after being
convicted of the murder of her husband.
Kristin’s appeal was based on ineffective counsel at trial. The argument runs that her defense attorneys should have pursued some toxicological issues that
they did not and which, if they had, might have resulted in a different outcome. One issue is whether the admittedly sublethal quantities of clonazepam and
oxycodone found in Greg’s body might have caused his death by way of synergistic drug action—acting together in a way that was more powerful than that
of either drug separately at the same levels. Another issue raised on appeal was the possibility that the fentanyl was administered postmortem. An expert
hired by Kristin noted that the postmortem specimens were not tested for fentanyl metabolites, and as a result, it was not certain that he had ingested the
drug before his death.
Re lect On It
Was there suf icient evidence to convict Kristin Rossum of poisoning Greg? Why or why not?
The protocols discussed are used in the most common of toxicological cases, such as DUI and DUID cases. Today these cases constitute a majority of the samples
seen by toxicologists. Make no mistake, poisonings and deaths are seen as well, but DUI and DUID cases are the most common. How do these cases make it to the
laboratory? The most common route is through a traf ic stop or an accident. Of icers determine if alcohol or drugs may be involved, and samples will generally be
collected at a hospital and taken for testing by the laboratory. But how is that determination made? This will be answered in the next section on how to recognize
drug and alcohol use in the ield.
5.3 Drug and Alcohol Recognition in the Field
Police of icers may receive training to recognize if drugs or alcohol might be present in a
person. Some states have what is called the drug recognition expert (DRE) program. Not all
of icers are trained as DREs. However, the program is expanding, so more of icers are receiving
this training, which goes beyond the standard to enable of icers to determine when a suspect
has used a drug and what class of drug it could be. Of icers do not try to determine the speci ic
drug, only a general group. The groups include depressants (including alcohol), stimulants,
hallucinogens, and also phencyclidine, opiate and narcotic drugs, cannabis, and inhalants.
Of icers will not consider common drugs, such as aspirin, in their determinations. They can
only determine if an impairing, abused drug might be present. The information gained by the
of icer at the scene can be used by the toxicologist to assist in analysis. Remember, however,
that the toxicologist will only use this information as an aid. The analysis is not tailored to the
results of the of icer’s investigation and report.
Drug Recognition Expert
Drug
Drug Recognition Experts: In the Line of Duty,…
Recognition (https://fod.infobase.com/PortalPlaylists.aspx?
Expert
wID=100753&xtid=52640)
From Title:
The following example will take us through a complete toxicology case in which the charges
will be DUI and DUID. An of icer responds to the scene of a simple accident, where a car has
struck a telephone pole. Upon questioning the driver, the of icer notices what seems to be the
odor of an alcoholic beverage on the driver’s breath. Something to note is that ethanol has no
odor; instead, it is the other components of the alcoholic beverage, such as tannins, oils, and
additives, that contribute to those smells. At this point, the of icer may ask the suspect to
submit to ield sobriety tests. These are called in some circles psychophysical tests or divided
attention tests. The of icer is trying to determine if the suspect could be impaired. The three
tests normally used in the standardized ield sobriety tests (SFSTs) are the walk and turn
test, the one leg stand test, and the inger to nose test (U.S. Department of Transportation
National Highway Traf ic Safety Administration, 2001).

Additionally, the suspect might be observed by the DRE. Certain aspects of behavior and
appearance indicate the possibility of drug use. These include the way the suspect answers
questions. Does the person answer the of icer’s question or exhibit a stream of consciousness
talking that bears no relation to the question? Does the person appear to be disheveled or
unable to stay alert? All of these characteristics can be used by the DRE to determine if a
suspect is under the in luence of a drug, and if so, the class to which that drug belongs.
A drug recognition expert explains how his work differs
from other police of icers who are only trained to
recognize impairment due to alcohol.
If the person being observed took a depressant, he or she may be lethargic and slow to respond or may fall asleep at inappropriate times. Of icers have observed
suspects who were placed in a squad car fall asleep even after an accident. If the person being observed has pinpoint pupils, this could indicate an opiate as
opposed to any other depressant, as most other depressants do not cause this condition. It is often very easy to determine if inhalants are the problem. Remember,
inhalants depress the central nervous system, causing drowsiness and sleep. Since these are so fast acting, there is usually evidence in the immediate vicinity, such
as the cans containing the gases. These should be collected as evidence, because by the time of icers take the person to a sample collection facility, he or she will
appear normal and the drug will have mostly cleared from the system.
If the person has taken stimulants, he or she may be very active and energetic or, depending on the stimulant, uncooperative and argumentative. Hallucinogens
can cause similar symptoms, but the behavior of a person using this class of drug may be more bizarre, and their affect and response to questioning will be less
coherent. The of icer may check for horizontal and vertical gaze nystagmus, uneven tracking of the eye, if the presence of a hallucinogen, in particular PCP, is a
possibility. The of icer will ask the person to follow an object as it is moved up and down and left and right in front of him or her. Normally, the eye can track
smoothly. It has been found that people using PCP cannot track smoothly up and down. Other drugs can cause uneven tracking in the side­to­side testing. Lack of
convergence, or the inability of a person’s eyes to converge (cross) on a subject in front of his or her nose, can also be a symptom of certain drugs. Table 5.1, the
drug recognition expert matrix, is a helpful tool for evaluating a person in the ield, although it should not be used to conclusively identify a drug in a person’s
body, since only scienti ic testing can do that.
Table 5.1: Drug recognition expert matrix
Depressants
Inhalants
Dissociative
anesthetics
Cannabis
Stimulants
Hallucinogens
Narcotic
analgesic
Horizontal gaze
nystagmus
Present
Present
Present
None
None
None
None
Vertical gaze
nystagmus
Present
Present
Present
None
None
None
None
Lack of convergence
Present
Present
Present
Present
None
None
None
Pupil size
Normal
Normal
Normal
Dilated
Dilated
Dilated
Constricted
Reaction to light
Slow
Slow
Normal
Normal
Slow
Normal
Little to
none
Pulse
Down
Up
Up
Up
Up
Up
Down
Blood pressure
Down
Up/Down
Up
Up
Up
Up
Down
Body temperature
Normal
Up/Down/Normal
Up
Normal
Normal
Up
Down
Source: Adapted from “Table 2: Signs typically produced by drugs in categories shown,” from “The drug evaluation classi ication program: Using ocular and other signs to detect drug intoxication,” by E. M. Kosnoski, R. L.
Yolton, K. Citek, C. E. Hayes, and R. B. Evans, 1998, Retrieved from https://www.researchgate.net/publication/13697760_The_Drug_Evaluation_Classi ication_Program_using
_ocular_and_other_signs_to_detect_drug_intoxication (https://www.researchgate.net/publication/13697760_The_Drug_Evaluation_Classi ication_Program_using_ocular_and_other_signs_to_detect_drug_intoxication)
This test could let the DRE know that the suspect has taken PCP and great care should
be taken with the individual, as many PCP users have violent episodes. Additionally,
PCP is a dissociative anesthetic, which means the suspect will not feel pain normally.
This can lead to a very dangerous situation for of icers and anyone else in the area.
Other hallucinogens, including cannabis, do not have this same effect.
If the suspect scores poorly on the SFST, the DRE may have a good indication of the
drug present in the suspect. He or she will be further interviewed and asked to take a
Breathalyzer test if alcohol appears to be present without other drugs, or a blood and
urine test if there is an indication that drugs other than alcohol are present.
Breathalyzer test units today accurately record the alcohol concentration in the breath.
There are many restrictions for Breathalyzer testing that are followed to make sure the
test is accurate. The individual being tested must be observed for 20 minutes prior to
the test to ensure that foreign materials have not been placed in his or her mouth and
that he or she does not belch or vomit. This rule was originally made for the protection
of the suspect, to ensure that no raw ethanol was in the suspect’s mouth. The presence
of alcohol in the mouth would falsely increase the breath alcohol concentration (BrAC).
In addition to the breathalyzer for alcohol, in the mid­2010s portable handheld
machines were introduced that can test for amphetamines, benzodiazepines, cocaine,
methamphetamines, opiates, and THC. An of icer takes a swab from inside the
suspect’s mouth and inserts it into the machine, and the results are ready in ive
minutes. These tests screen for recent drug use, not chronic use, and the results have
been deemed admissible in court (Strandberg, 2016). This is a much faster and easier
way to check if a driver is impaired than taking a suspect to a second location for a
blood or urine sample. Implementation of this technology is still in the early stages,
but perhaps one day it will be as common as a roadside breathalyzer.
Marion R Walding/Associated Press
Some bars are beginning to install Breathalyzer machines on their
premises. Do you think this idea would help prevent more people from
driving before they are sober?
5.4 Additional Drug and Alcohol Testing
Most people may not be aware, but in most states, when you sign your driver’s license, you are entering into an agreement with the state that if you are stopped
for DUI you agree to submit to testing. This has been called “implied consent.” This testing could involve collection of a DUI kit for blood and urine testing, or it
could mean Breathalyzer testing. In 2016 the U.S. Supreme Court changed the way blood could be taken (Birch ield v. North Dakota, 2016). Now, if blood is to be
taken, a search warrant must be obtained by law enforcement of icers, signi icantly impacting the original idea of implied consent. Regardless, some kind of
con irmation of the presence of alcohol or drugs in the suspect needs to be proven by a laboratory in order to con irm the ield testing in court.
The use of Breathalyzer testing and the rules for the administration of the breath test have been changed in recent years by the defense community. Defense
attorneys have tried to say, for instance, that because a person had dentures, his or her Breathalyzer test was invalid. This has given rise to myths about beating
the Breathalyzer test, including the idea that putting a penny in your mouth can produce a bad result. While it does not interfere with the test, of icers do need to
be aware of the fact that suspects may try to hide items in their mouth.
In addition, suspects are now taken to a law enforcement facility for a Breathalyzer test instead of using a portable Breathalyzer test (PBT) unit in a squad car. The
PBT can be used for probable cause but not as inal evidence in a court. The concern is that since the PBT is in a car and exposed to bumps, accidents, and other
factors, the calibration may not be correct and the results may not always be accurate.
Instruments must be routinely checked for reliability and calibrated for accuracy. Test administrators are trained to operate, function check, and administer the
tests, since this is one of the most routinely challenged aspects of DUI cases. All log books and calibration and function check data must be kept in order to meet
these challenges. During the observation period, the suspect will be asked more questions about health, use of alcohol or drugs, and food consumption. This will
be used in court and by the toxicologist. The answers collected can allow the toxicologist to perform a back extrapolation, which we will discuss later.
Think About It
What do you think of implied consent? Will the recent ruling damage the ability of of icers to con irm impairment of suspects?
Hospital Blood and Urine Samples
If the suspect agrees to a blood draw and gives a urine sample, or if the Breathalyzer test is negative, he or she will often be taken to a hospital for the draw and
collection. Blood draws are routine in the case of an accident. The routine hospital blood draw will allow the hospital to test serum for alcohol. Serum is the luid
left behind when all of the blood cells are removed. This process concentrates the alcohol in a smaller volume, making it necessary to convert the serum alcohol
concentration into a whole BAC. This is easily done, since many studies have concluded that the average serum to whole blood conversion ratio for people is 1.18
to 1 (Charlebois, Corbett, & Wigmore, 1996). To convert, a toxicologist will divide the serum alcohol concentration by 1.18 and obtain the whole BAC.
Sample Collection for the Toxicologist
In cases that involve DUI and DUID, chain of custody is assisted by the use of prepared kits from various scienti ic companies, one of which is Tri Tech, Inc. As you
may remember from our discussion in Chapter 2, chain of custody applies to every kind of evidence, and it must document who handled the evidence, who
analyzed it, how it was treated, what preparation was done to it before packaging, and where it was stored. Any breaks in the chain of custody can result in the
evidence being inadmissible in court.
The blood and urine samples for forensic toxicologists are separate from the hospital samples, and the use of the prepared kits is a necessity. The kits are sealed
boxes containing the paperwork and vials necessary for sample collection. When needed, the seal on the box is broken to allow access to the contents. A typical kit
contains two vacutainer tubes. These will have gray tops and contain a preservative and an anticoagulant. The preservative keeps the blood from spoiling, and the
anticoagulant keeps the blood from clotting. Both are necessary for the toxicologist to test the blood and arrive at a reliable BAC. There are two labels for the blood
tubes, on which the name of the suspect, the date and time, the of icer’s name, and the name of the individual drawing the blood are written. This can then be
placed on the tube to seal it.
The urine collection is accomplished using two plastic bottles in the kit. These bottles are clean and dry and will provide enough sample for testing at the
toxicology laboratory. There are labels for these bottles similar to those for the blood tubes that can be used to seal the bottles. The urine collection is
accomplished while maintaining the dignity of the suspect. This is often done by a same­sex of icer accompanying the suspect to a restroom prepared for sample
collection. The suspect is searched to make sure he or she does not have anything that could be used to contaminate the urine sample. The suspect has the privacy
of a stall, but the of icer is outside to receive the sample immediately after it is placed in the vial by the suspect.
Paperwork is included to provide a history of the incident, be it an accident or traf ic stop; suspect information, including medications being taken and possible
drug or drinking history; and a request from the of icer to the laboratory indicating what analysis should be completed. While the collection is taking place, the
suspect will be examined and observed by medical personnel who can help determine the possible drug class that was ingested by the suspect. This information
will be communicated to the of icer, and further discussion with the DRE may take place to arrive at the possible cause of impairment. The DRE may compile
enough information to write the report that can later be used in the trial. When the collection is complete, there is a form for the toxicology laboratory that will let
the toxicologist know what is possibly in the blood and urine. Everything will be placed back in the original box, sealed using a label, and sent to the toxicology
laboratory.
Transportation of samples to a forensic laboratory should take place as soon as possible. While storage at room temperature for a time is not harmful to the
samples, care should be taken to prevent exposure to extremes in temperature. Excessive heat, like storing the samples in the trunk of a car on a hot summer day,
will destroy the blood samples and promote growth of bacteria in the urine. Excessive cold weather with temperatures below freezing could cause the blood to
freeze and shatter the tubes. Samples can be kept safely in a refrigerator not used for food as long as proper chain of custody is kept and the refrigerator is in a
secure area of the building.
5.5 Toxicology Laboratory Testing
Once the evidence has been received in the toxicology laboratory, it will be signed into the laboratory, and each item of evidence will be given a unique identi ier.
This will prevent any sample mix­up in the future. The evidence will be stored in a locked area under refrigeration. When it is to be analyzed, it will be moved to
the testing area. The toxicologist will see the information from the of icer’s observations and the medical personnel’s evaluation. This can be used by toxicologists
in their analysis to assist in testing, but it will not be the sole basis for their tests. Toxicology laboratories have well­documented rules to determine who can direct
a laboratory and who can do the testing (SOFT/AAFS, 2006). The analysts must follow protocol when analyzing evidence. These rules for analysis make sure
complete and unbiased testing is done in each case presented. One of the irst rules is that the toxicologist should only sample from one blood tube and one urine
vial. The remaining sample should be kept in case the defense wants testing completed by their toxicologist.
Analysis is always completed with control samples, as we discussed in Chapter 1.4. These controls are a large part of the quality assurance and quality control
process. They are samples from the same matrix (blood or urine) that is being tested. There are several types of controls used in the toxicology laboratory.
Positive controls have drugs in them. Analysis of this control lets the toxicologist know that the procedure worked as expected, and if drugs were in the suspect
sample, they would be found. Negative controls do not have drugs in them. These samples let the analyst know that the testing worked and there was no
contamination of samples in the extraction and testing process. Quantitative controls are used if the sample is to be tested for the amount of drug present. These
have a known amount of drug present, and after completion of the analysis using these controls, the analyst will know that the process worked and gave the
correct value of drug present. If all controls give their proper answer during analysis, the analyst knows the procedure worked from the irst step in the extraction
process all the way through instrumental analysis.
Analysis of Cases
The analysis of other samples at the forensic toxicology laboratory is much the same as
those submitted for drug analysis. Preliminary tests indicating possible classes of
drugs or poisons that may be present are completed. Finding what is possibly present
in a sample is often referred to as qualitative testing. Preliminary testing includes use
of color reagents that react based on the possible presence of a drug. Different types of
immunoassay tests also provide preliminary information about the classes of drugs
that may be present. These tests use a specially designed antibody to react with a drug
in the urine or other luid. When a drug is present, the reaction will yield a product
that can be detected and measured in the instrument, letting the analyst know that a
certain drug or drug class is present in the sample. After determining what class of
drug might be present, con irmatory testing is done to conclusively identify the drug
or drugs present. Following this, testing to establish the concentration of drugs in the
body can be completed. This is called quantitative testing. In every case, qualitative
testing is completed because the forensic toxicologist must report what drugs or
metabolites were in the suspect’s system to the trier of fact. The completion of
quantitative testing depends on the type of case and the individual statutes of the state
where the crime was committed.
Mike Derer/Associated Press
Samples at forensic toxicology laboratories are run through various tests
for analysis, including immunoassay tests. Do you think individual states
should be allowed to determine what BAC level implies impairment?
In every DUI case, a quantitative test will be completed. Each state has a BAC that
legally establishes impairment. Because of this, the toxicologist must know the
concentration for testimony in court. In a case in which a controlled substance is
involved, some states have what is called a per se law. This means that the toxicologist does not have to quantitate the controlled substance that is present if it is
termed a drug of abuse. This is because the per se law deems that any amount of that substance found in the body classi ies the suspect as impaired. This includes
drugs like cocaine, methamphetamine, PCP, and LSD. Many cases involve prescription drugs. Some of these drugs may be controlled, as we saw in Chapter 4, but
are not considered drugs of abuse. In cases involving these drugs, toxicologists may quantitate the drugs present if a blood sample is submitted. They will not be
able to tell if the person was impaired, but they can obtain a level of drug in the blood. There are three general levels of drug in the body that can be described.
A subtherapeutic level of drug means that there were drugs in the person’s system but the level was low enough that the drug likely did not have an effect. This
could be described as a person who takes a depressant drug as a sleep aid. The next day, if he or she is involved in an accident, there might be a small amount of
the drug remaining in the body. The toxicologist would ind it, quantitate the drug and ind that indeed, the level was so low that the person was most likely not
affected by the drug. The trier of fact could then take that into consideration during deliberations and possibly ind that the accident was just an accident rather
than an accident caused by an impaired person.
A therapeutic level of drug means the drug is in the person’s system and is at a level that the drug’s effects are present. Again, the toxicologist cannot say the
person was impaired, but he or she can say that the drug was present at such a level that its effects could have been a factor in a case. An example of this involves a
person who takes a depressant drug and tries to drive immediately after consumption; when the drug is distributed in the system, the person dozes off in the car
and is involved in an accident. The toxicologist quantitates the drug and inds it to be in the therapeutic range. The toxicologist relays this to the court and
describes how the effects of the drug present themselves. The toxicologist says that the levels of this depressant could cause drowsiness, decreased attention,
slowed re lexes, and relaxation. The police of icer would need to ill in the details of how the suspect was acting at the scene. If what the of icer reveals and what
the toxicologist describes are similar, the trier of fact could ind that the person was impaired and reach a verdict re lective of these facts.
The third level that a toxicologist looks at is the lethal level, to see if there is enough drug in the system to kill the individual. This usually involves postmortem
toxicology. For example, a body is found with pill vials nearby, or a body is found with a syringe and packet containing illegal drugs. In either case, the toxicologist
identi ies the drug in the body and quantitates to ind if the level present was at or above the lethal level. If so, it would be reported and would help the coroner or
medical examiner reach a conclusion about the cause and manner of death in the case. Toxicology testing takes time. That is why you may have noticed that in
high­pro ile cases, the medical examiner or coroner waits for the toxicology results to come back before making statements about the cause of death. One must
note that not everyone will die just because there is a high concentration of drug in their system. Many addicts can survive a level that would be lethal to a novice
user because they have developed tolerance to the drug. This does not indicate lack of impairment; it only indicates that they can take higher doses of drugs and
not die.
Think About It
The per se law states that the presence of an abused drug, no matter the quantity, renders the person impaired. Do you think this is a fair law? Why or why
not?
Drugs
We have discussed the entire process from irst observation by the of icer through analysis by the toxicologist. However, what does this testing mean for the law
enforcement of icer, victim, and suspect? Through analysis, the toxicologist can identify drugs and ethanol in the provided samples. A report of these indings is
sent to the law enforcement agency that submitted the case. If no drugs or ethanol are found, the case may be dismissed. If drugs are found, the suspect may be
charged with DUID. If the drugs found fall under the abused drugs list, then any per se law goes into effect. In other words, the mere presence of drugs in the
suspect’s samples indicates impairment. If prescription drugs are found and quantitated, the toxicologist will testify at trial as to what the level means in normal
people. This seems very simple; however, there are other toxicological issues that can come into play. Remember that drugs are metabolized in the body. These
metabolites may be inactive but may remain in the blood or urine longer than the active parent drug.
Let’s take cocaine as an example. Remember, cocaine is a controlled substance. It is a stimulant and can cause a decrease in judgment and inhibitions that can lead
to accidents or improper behavior. Cocaine is metabolized to benzoylecgonine, an inactive compound that remains in the body for a while after the cocaine has
disappeared. If the analyst only inds the metabolite, does this mean the person was not impaired? The defense will certainly try to present this point. The analyst
must remain unbiased in the case. The analyst can state that benzoylecgonine results when cocaine is taken but will not be able to say for certain that there was
cocaine in the system at the time of the traf ic stop. The evidence provided by the of icers on the scene will be used to convince a judge or jury that the person was
under the effect of the drug when stopped.
Ethanol
Ethanol is much easier to work with than illicit drugs. All states have a level of ethanol at or above which the suspect is deemed to be impaired. Most states use the
level of 0.080 g/dl. (Remember that a gram is around ¹∕₂₈ oz.; a “dl” or deciliter is ¹∕₁₀ of a liter, or a little less than ½ cup.) In layman’s terms, this means that in
every 100 ml (one deciliter) of blood, there are 0.080 grams or 80 milligrams of ethanol. The amount of alcoholic beverage it takes to get there is dependent on the
weight and gender of the individual. There are several charts available on the Internet that provide rough estimates of alcohol concentrations based on weight,
gender, and the number of drinks consumed. An example of one of these charts is shown in Figure 5.1. In these charts one must remember that a “drink” is usually
de ined according to Table 5.2.
Figure 5.1: Blood alcohol concentration
As shown in the chart, having one to two drinks can signi icantly change a person’s BAC, depending on his or her weight
and the amount of time between each drink. Do you agree that having a BAC of 0.080 g/dL (or .08%) should result in a
DUI? Why or why not?
“Actions Resulting in Loss of License,” by State of California Department of Motor Vehicles, n.d. Retrieved from
https://www.dmv.ca.gov/portal/wcm/connect/7ed001aa­cc59­4ba4­897c­c0f7aac4d7c2/chart_10_bac_chart.pdf?MOD=AJPERES&CVID=
(https://www.dmv.ca.gov/portal/wcm/connect/7ed001aa­cc59­4ba4­897c­c0f7aac4d7c2/chart_10_bac_chart.pdf?MOD=AJPERES&CVID=)
Table 5.2: The amount of alcohol in different drinks
Drink
Amount
Alcohol concentration
Alcohol present
Normal American beer
12 ounces
4% or 8 proof
0.48 ounces
Wine
6 ounces
8% or 16 proof
0.48 ounces
Mixed drink
1.25 ounces
40% or 80 proof
0.48 ounces
Mixed drink
1 ounce
50% or 100 proof
0.48 ounces
As you can see, the “normal” drink has approximately ½ ounce of pure alcohol in it. However, when people drink, they often do not have a normal drink. How
many times have you seen offerings at bars of “tall beers” that contain 16 or 20 ounces of beer? The same can happen with mixed drinks containing higher proof
liquors. People may not actually know how much alcohol they are putting into their system.
Think About It
The bars that offer large beers often offer craft beers as well. Some of these can contain up to 14% alcohol, compared to the normal 4%. What added
danger does this present to the customer?
People also do not respond in the same way to a particular BAC level. One person may appear normal at a 0.080 g/dl level, but another person may be obviously
impaired.
This difference in response is called individual variation and can be due to genetics, previous alcohol use, or a number of other factors. One thing to remember is
that even when people look like they are sober, alcohol is depressing inhibitions and judgment. This depression is a major cause of accidents. Drivers get into
dangerous situations and do not use good judgment. At higher alcohol levels, the impairment of re lexes and visual disturbances contribute. If enough alcohol is
consumed, a person will pass out, can go into a coma, and can die. Death can happen due to aspiration, in which a person who has passed out and is lying faceup
can vomit and then inhale the vomit into the lungs. Death can also happen due to excessively high alcohol concentrations. The average person dies at a level of
0.450 g/dl.
Alcohol in the Body
When a person begins drinking, the alcohol is absorbed into the bloodstream and distributed through the body. This is the absorption phase. Once a person stops
consuming alcohol, he or she will reach a peak blood alcohol level and then the level will begin to decrease. The time of this peak is dependent on food intake. If a
person drinks on an empty stomach, the peak is reached in 15 to 30 minutes. If a person has been eating, the time to peak absorption can be from 60 to 90
minutes (Baselt, 2011). Regardless, once the peak alcohol level has been reached, metabolism takes over, and the level begins to decrease. The average metabolic
rate for alcohol is 0.015 g/dl/hr. This means that individuals who are at a 0.080 g/dl at their peak will be approximately 0.065 g/dl 1 hour later. This decrease
continues until the alcohol is gone. This is a slight oversimpli ication, since metabolism is going on at the same time as absorption, but levels rise as long as intake
of alcohol exceeds metabolism, and levels decrease when metabolism is greater than intake. Hence, 0.015 g/dl/hr is an average (Baselt, 2011). Some people
metabolize more slowly and some more rapidly, depending on health, genetics, and other factors.
Alcohol is metabolized in the liver. There are two enzymes involved in the process. The irst, alcohol dehydrogenase, converts ethanol to acetaldehyde. The second,
aldehyde dehydrogenase, converts the acetaldehyde to acetic acid. The irst enzyme appears to operate as long as alcohol is present. The second enzyme appears
to have various genetically controlled forms that operate differently. Depending on the form a person has inherited from his or her parents, the acetaldehyde
metabolizes at different rates. Some metabolize the acetaldehyde ef iciently, while others metabolize more slowly, allowing acetaldehyde to build up in their
system. Since this is genetic, individuals may not know how they will metabolize until they consume ethanol. If they have a slow­functioning aldehyde
dehydrogenase enzyme, they will build up acetaldehyde in their system and experience the associated lushing and nausea.
Calculations
There are some calculations that the toxicologist can perform regarding alcohol. As mentioned previously, if serum is used to determine alcohol concentration, the
level must be converted to a whole BAC, because that is the way the impairment level is written into the law. Another calculation can assist in determining the
approximate BAC at the time of an incident, even when the blood or Breathalyzer test is not completed until hours later. Remember that on average, a person
eliminates approximately 0.015 g/dl of ethanol per hour. If the toxicologist knows an alcohol level and the time difference between the test and an incident, such
as an accident or traf ic stop, 0.015 g/dl can be multiplied by the time difference in hours, calculating the amount of ethanol eliminated. That amount can be added
to the level from the test; the result is the approximate level at the time of the incident. Finally, the toxicologist can estimate the amount of ethanol in a person’s
system and convert it to an approximate number of drinks in the individual’s system. This can be done if the toxicologist is provided with the person’s weight,
gender, BAC, and what the person was drinking. This becomes an issue when the driver states that he or she only had a couple of drinks, but his or her BAC is
exceedingly high. This can be the result when people forget how much they drank or are not drinking “normal” drinks.
While the bulk of the forensic toxicologist’s duties will be related to human performance and inding drugs or alcohol in submitted samples, there are other
aspects to the analysis performed by these scientists. Drugs can be delivered to victims unknowingly. Some of these drugs are given by a suspect to render a victim
unconscious so they can be sexually violated. This is often known as drug­facilitated sexual assault.
5.6 Drug­Facilitated Sexual Assault
Another analysis completed by toxicologists involves the crime of drug­facilitated sexual assault (DFSA). Giving a person a drug for the purposes of rendering
him or her incapable of giving informed consent to sex can result in charges over and above rape at trial. Most of the drugs used are in the depressant category,
and most of the time alcohol is also involved. When a victim of rape goes to a hospital, the primary concern is the health and well­being of the individual. Samples
speci ically related to the assault are collected, but occasionally drugs will not be considered.
As was mentioned brie ly in Chapter 1, some nurses receive special training to deal with sexual assault. These are called sexual assault nurse examiners
(SANEs). These specially trained nurses have added knowledge related to sample collection, preservation of the sample, maintenance of chain of custody, and
testimony in court. In areas such as Chicago and the rest of the state of Illinois, where SANE nurses have been a part of evidence collection in sexual assault cases,
prosecution rates have increased because of their expertise (Illinois Attorney General, 2010). Part of their training includes determining whether drugs have
played a part in the crime.
If drugs may be involved, a urine sample is necessary. The urine can be tested for the
presence of drugs and alcohol, but no levels will be determined. Because some of the
drugs used are very potent and have short half­lives in the body, such as alprazolam,
the sample must be collected as soon as possible. Additionally, the toxicologist must be
made aware of the nature of the crime, since some drugs, such as GHB, need
specialized testing. Some testing may be completed at a hospital, but remember that
although hospitals can determine that a depressant is present, they cannot directly
identify the drug. For court purposes, the identi ication of the drug is essential, and
since many hospitals do not perform con irmatory testing, the samples must be sent
outside to testing laboratories.
One of the drugs that received a great deal of press as a date rape drug was Rohypnol,
the standard dosage form of lunitrazepam. This drug was known on the street as
“roo ies.” Flunitrazepam is a potent benzodiazepine that causes sedation, muscle
relaxation, loss of anxiety, and loss of inhibition. This drug is also known to cause
amnesia in the victim. It accomplishes this so well that another of the street names for
World History Archive/Superstock
Rohypnol is the “forget me drug.” Because of its misuse, the manufacturer has added a
dye to the formulation to make it obvious that a drug was added to a potential victim’s Although Rohypnol has never been approved as a legal drug in the
United States, in other parts of the world, it is available by prescription
drink. Rohypnol is given in 2 mg dosage forms, so it is fairly potent; however, it has a
to treat insomnia.
half­life of about 20 hours. This means it can be detected in the urine for about 3 days.
Rohypnol also has a metabolite that can be detected in the urine, aiding in analysis.
This drug has not been approved for use in the United States by the FDA, so it has always been illegal and unavailable unless purchased outside the country and
brought in surreptitiously.
Other benzodiazepines have been used in DFSA. Benzodiazepines are often used because, as mentioned in Chapter 4, benzodiazepines react in a synergistic
manner with alcohol. That means the victim given a benzodiazepine­laced beer acts as though he or she had three to ive beers, or had taken three to ive doses of
benzodiazepine, instead of just two. The benzodiazepines are found in the urine through normal testing in the toxicology laboratory. The major concern is passage
of time between dosing and sample collection. The more time that passes, the less likely the toxicologist is to ind the drug.
Other drugs require more specialized testing. GHB has an extremely short half­life, between 20 and 60 minutes (Baselt, 2011). This means that 4 hours after
dosing, over 93% of the GHB is metabolized. GHB requires specialized analytical testing not normally pursued unless speci ically requested. Additionally, GHB is a
compound found naturally in the body. Though it is at a very low level, its presence poses a serious problem for the prosecution of a case. If DFSA is suspected, and
the victim arrived at the hospital hours after the incident and urinated before going to the hospital, analysis cannot be completed for GHB, as nearly all evidence
has been eliminated. If GHB is found in this case but is detected at the level normally found in humans, the toxicologist could not say the victim was dosed with the
drug. What has been found may just be the naturally occurring level in the person. The toxicologist can only state that GHB was used in DFSA when the level is
higher than that seen in endogenous levels.
One might ask, if a case is submitted to the toxicology laboratory and is listed as DFSA, does the toxicologist only look for drugs associated with that crime? The
answer is no. The toxicologist will still examine the sample for all of the drugs as standard procedure but will do additional testing for date rape drugs. It is
important to ind all drugs present in the urine. This can make some victims uncomfortable, especially if they have engaged in recreational drug use, such as
smoking cannabis. Care must be taken to make victims comfortable and let them know that the recreational use is not of concern to law enforcement.
The toxicologist will not be able to tell the impairment level of the victim during the assault. Remember, urine is not quantitated for drug levels, since urine levels
cannot be related to impairment levels; if any information about drug levels is needed, blood must be tested quantitatively. The toxicologist may be able to provide
information on the effect of drugs alone and in combination with other drugs. However, there will most likely not be any of icer who can testify about impairment,
since the victim will most likely not get to the hospital for hours after the crime takes place. This will make any determination of behavior at the time of the crime
nearly impossible. The importance of the toxicologist’s testimony is that the drug was found and the exact identity of it was determined. After that, the drug must
be tied to the suspect, and it must be shown that the victim was not taking the drug of his or her own accord. The toxicologist will relay the complete indings of
the analysis. If recreational drugs or alcohol were found in analysis, this will be disclosed. The toxicologist will not be able to say how the drugs got into the victim,
only that they were present.
Think About It
Since the SANE program is helping in the judicial process for DFSA cases, do you think that other medical personnel could receive training to assist in other
types of cases? What types of cases do you think would bene it?
5.7 Forensic Urine Drug Testing
The inal topic for discussion in this chapter is forensic urine drug testing (FUDT). In today’s employment climate, most people have probably been drug tested.
FUDT started as employment drug screens. It has spread into the law enforcement world through testing of urine of probationers and parolees, as well as testing
of athletes for drugs of abuse and performance enhancement. It has even spread into the horse racing industry, where winners have their urine tested for
proscribed drugs. For our purposes, we will stick to human testing for law enforcement, though this closely mirrors the screening completed on applicants for jobs
and that used when employees are randomly drug tested in the workplace.
Urine drug screens normally look for what have been referred to as the NIDA­5, the ive classes of abused drugs checked for in laboratories as determined by the
National Institute on Drug Abuse (NIDA). These are amphetamines, opiates, phencyclidine, cocaine, and cannabis. These were historically the drugs and drug
classes most abused. Testing begins on samples using immunoassays. This test is the same screening test used in the forensic and medical industries. At irst, this
was the only test done for workplace testing. Unfortunately, many false positive results were seen. For example, people who had taken cough syrup with
phenylpropanolamine were listed as positive for amphetamines. The conclusive identi ication of drugs eliminated the false positive tests in the amphetamine
class. Another problem was seen with opiates. Reports appeared of people who had submitted urine samples that tested positive for opiates after they had just
eaten something with poppy seeds. Research was completed, and it was found that if a person consumed enough poppy seeds and gave a urine sample within
several hours of that consumption, it was possible to trigger a positive test. Guidelines were again set up so that con irmation would take into account the
possibility of poppy seed consumption. Today this is not really a problem.
While false positives were an issue in the past, safeguards have been instituted that make false negative results unlikely. A false negative would result when
testing indicated there was no drug present when in fact there was. Many people have tried to alter their urine samples so that the drug that might be present
would be missed in analysis. These problems have been addressed, as well.
The NIDA was the original agency that licensed testing facilities. It also instituted the guidelines for acceptable testing to avoid false negatives and false positives
from the laboratories doing the FUDT. These included the con irmation of the identity of drugs found in samples. They also took into account the fact that people
might have passed through rooms where drug use was ongoing but did not participate. These people might have had passive contact and been exposed to drugs
without using them and could have trace amounts in their system through passive inhalation. Today the FUDT laboratories use immunoassay testing to ind if
drugs might be present, and the drugs are then con irmed using gas chromatography/mass spectroscopy (GC­MS). The immunoassay screening tests have cutoff
levels for the various classes of drugs to eliminate the possibility of positive results based on passive inhalation. What this means is that each drug class has a level
greater than zero (no drug present), which would still be considered negative. If the immunoassay tests indicate levels less than the cutoff value, the sample is
considered negative for drugs, and testing is complete. If the sample gives a reading above the cutoff level, it is considered positive, and the sample is isolated for
con irmatory testing with GC­MS. This inal test will tell which drug is present in the sample. If, for instance, the drug found is phenylpropanolamine, which is a
common component in cold medications, the result will still remain negative. If the drug is methamphetamine, the report will read as positive for that drug.
There are people being tested who have become aware of the procedures being used and tried to beat the test through adulteration, or the intentional addition of
some chemical for the purposes of interfering with the testing processes, of their urine samples. The goal of adulteration is to create a false negative test result—in
other words, affecting the testing in some way so that a person who has used drugs will not get caught. Since the testing only worked with urine at normal levels
of acidity and alkalinity in people, those who were afraid they might give a positive test result would try to alter the pH (acidity) of their urine. Some would drink
vinegar to make it more acidic. Others would add bleach to their samples to make it alkaline or basic. Other tricks were used to “beat the test” as well. Some
people substituted drug­free urine for their own urine. They would get a sample of urine from a friend who did not use drugs, conceal it, try to carry it into the
testing facility, and then place it in the sampling cup instead of their own urine. In some facilities this worked for a while. However, the industry was forced to
become more sophisticated in its methods of testing. Now, the facilities have methods of checking the temperature of the urine. Urine carried outside the body is
too cool and will no longer be accepted. Another method of trying to beat the test was to take herbs and drink large amounts of water. This did not eliminate all of
the drug but lowered its concentration so testing indicated levels below the cutoff, resulting in a negative report. Again, a method to detect this was found. The
body creates a compound called creatinine that is excreted in the urine. In healthy individuals, there is an average concentration range for this compound.
Drinking large amounts of water dilutes not only the drug concentration but also the creatinine concentration. This serves as an indicator that diluting and
lushing is taking place.
If it seems like a great deal of time and effort has gone into detecting people trying to beat the test, there is a reason. Some states have passed legislation
mandating that FUDT laboratories report possible adulteration of urine samples for the purposes of trying to beat the test. If, for instance, a collector noticed the
urine had a very low temperature when collected, it would be stated on the report. The same would happen if the urine had a very high or low pH, or if the
creatinine level was low and far outside the normal range. Employers have learned not to look at just the results but also the condition of the urine sample, noting
indicators that someone has tried to beat the system. While the states do not have a vested interest in the information reported by the laboratories, the employers
gain information about the people they are getting tested.
Forensic toxicology laboratories follow many of the same guidelines for analysis in urine samples being tested. Many of the cases that require such testing are
probation cases. Many parolees are randomly chosen to give urine samples to prove they are not using drugs. When this sample comes into a lab, under seal and
with complete chain of custody, the analyst will run preliminary testing for the ive classes of abused drugs. If the preliminary testing is negative, the case will be
closed and reported as negative. If drugs are indicated in the preliminary test, then conclusive testing will be completed to identify the drugs. The report will
re lect what drugs were identi ied.
In spite of the protocols that laboratories have in place, one aspect of testing urine is dif icult to catch. In casual users, the drugs of abuse that are being tested for
are undetectable in the urine after 72 to 96 hours have passed, and with some drugs, even less time is needed. This means that if someone is prepared for the test,
he or she can abstain from drug use for 3 or 4 days and will test as drug free. A test developed in the past decade has expanded the drug detection limits for
forensic and employment testing. Techniques have been developed that allow testing of hair for the presence of drugs. Since nutrients to the root of the hair are
delivered by the blood, drugs in the blood can also be deposited in the hair. After the drugs are deposited, they will not leave, but are instead trapped until that
section of hair is cut off. This allows the testing laboratory to have a sample with a longer record of drug use.
Testing facilities have had to develop techniques that can provide information that the drug came from inside the hair and was not deposited on the outside of the
hair, as would happen with passive contact. Once these techniques were validated, testing could give a record of drug use much longer than any urine sample.
Head hair grows on average about 1 cm, or about ½ inch, per month. A hair sample is collected by cutting hair off next to the scalp in an amount about the
diameter of a pencil. This hair sample can be sectioned into ½­inch pieces. Each section can be tested for drugs. Typically, only the last 3 inches, or about 6 months
of growth, will be tested. This will tell the drug history of the individual for that period of time. Of course, people have again tried to beat the test by shaving their
heads, but a drug can be found in any hair. One aspect to hair testing should be considered with care. This testing cannot tell exactly when a person used drugs; it
only shows that a person took drugs during a month of time as shown in a certain section of hair. Additionally, there is nothing in this test that indicates
impairment due to the drugs. This testing is much more expensive than urine testing, so if a company uses this type of testing, it is serious about drugs in the
workplace.
Think About It
FUDT is also used in many other ways. Where do you think this testing is used outside of forensics?
Conclusion
Forensic toxicology is used in a wide variety of casework in forensic science. The testing can determine if a person had drugs in his or her system, provide a blood
alcohol level that can be used in the determination of DUI cases, and tell if a person died of drug overdose or was poisoned by a toxic compound. Testing
procedures are extensively validated, and controls are run on a daily basis to con irm the functioning of the instruments in the toxicology laboratory. The
toxicologist has the tools necessary to assist the case in the identi ication of myriad compounds for forensic use and has the knowledge to assist the courts in the
determination of what the effects could possibly have been. As the drugs become more potent and new designer drugs come on the market, the challenges facing
the toxicologist will keep the exciting ield of forensic science continuously growing.
Key Ideas
•
•
•
•
•
•
•
•
•
•
•
•
Toxicology is the study of the effects of poisons and toxins in the body. Forensic toxicology applies that information to the courts.
Forensic toxicology can be used in poisonings and human performance cases. The majority of cases forensic toxicologists deal with are DUI and DUID
cases.
Several types of poisons that can be encountered in forensic toxicology cases include heavy metals, pesticides, carbon monoxide and other gases, drugs,
and alcohol.
Chain of custody is important in forensic toxicology cases to make sure the evidence is admissible in court.
Qualitative testing tells what is in a sample, while quantitative testing tells how much of the substance is present in a sample.
Drug recognition experts are police of icers trained to assess suspects who may be under the in luence of drugs. Through interviews, testing through the
SFST, and general observation of the suspect, they may be able to ascertain if the suspect is under the in luence of depressants, stimulants, hallucinogens,
phencyclidine, opiates and narcotics, inhalants, or cannabis.
Preliminary or screening tests tell what class or category of drug may be in a sample; con irmatory tests tell with certainty what drugs are present and the
quantity.
Toxicology testing is rigorous and involves the use of positive and negative controls to make sure all testing is functioning properly and quantitative
controls to make sure all quantitative results are accurate.
Drugs generally are prosecuted under per se laws, which means that any amount of drug in the system indicates impairment, while ethanol relies on
certain levels in the blood or breath to determine impairment by statutory de inition.
Drug­facilitated sexual assault occurs when a person tries to incapacitate or render a victim unable to make informed decisions about engaging in sex
through the use of drugs.
Forensic urine drug testing has become highly controlled to make sure that correct results from testing are generated by the testing laboratory and also
that adulteration of samples by the person being tested is detected and reported.
Hair testing is now being used and can increase the detection time of drugs in people. Care must be taken with the results to make sure no
misrepresentation of the indings occurs.
Critical­Thinking Questions
1.
Knowing what you know about ethanol and BAC, how would you explain in court what it means to be “driving under the in luence,” if you were a
toxicologist testifying in a court case about someone driving under the in luence of alcohol and hitting a pedestrian?
2. Arsenic has been used in poisonings because it could be misdiagnosed as a disease. Do you think that a clever poisoner could get away with murder today
if he or she chose the right poison?
3. The organophosphate pesticides have been seen in accidental poisonings. What other examples can you think of that use these compounds? What steps
do you think should be taken to prevent accidental poisonings?
4. DRE programs are becoming more prominent in of icer training. Do you think this program should be a requirement to become a police of icer? Why or
why not?
5. If a person is found dead with many pill bottles around him or her, does this necessarily mean the person died of a drug overdose? Explain your reasoning.
6. Do you think the DRE will ever take the place of a toxicologist in court? Why or why not?
7. A person fails his or her SFST and has a fruity odor on the breath. Could this be anything other than alcohol intoxication? If so, what?
8. There is a lot of time spent analyzing controls in toxicology. Why do you think all of these controls are necessary?
9. If the average person can die at a 0.450 g/dl level of ethanol, why are some samples seen that have higher levels in living people?
10. The SANE nurses can help get good evidence for testing. How is this affected if the victim waits 2 or 3 days before going to the hospital after an assault?
11. If a person can be shown to have altered his or her urine to try to get a negative FUDT result, what do you think should be done?
Key Terms
Click on each key term to see the de inition.
acute
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
Immediate, or seen very soon after; acute tolerance, for example, is seen within hours of exposure to a compound.
adulteration
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
The act of adding a chemical to a sample for the purposes of interfering with testing by a hospital or forensic laboratory.
blood draw
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A sample of blood taken in order to test for medical or forensic purposes.
breathalyzer test
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A device used to determine the breath alcohol concentration (BrAC) of a suspect.
carbon monoxide (CO)
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A highly toxic gas, usually produced by combustion of hydrocarbon fuels.
chronic
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
Something that takes place after a longer period of time; for example, chronic dosing means giving a drug for a long period of time, as opposed to a single dose.
con irmatory testing
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
Used to conclusively identify the particular drug or drugs present after it has been determined that a particular class of drug might be present.
date rape drug
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A drug that is used to render a victim unconscious or incapable of saying yes or no to sexual intercourse.
drug­facilitated sexual assault (DFSA)
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
The process by which a person tries to incapacitate or render a victim unable to make informed decisions about engaging in sex through the use of drugs.
drug recognition expert (DRE)
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A police of icer trained to evaluate suspects and determine if drugs may be involved in their behavior.
false negative
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A sample does contain a drug, but this drug is not found during testing.
false positive
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A sample does not contain a drug, but testing indicates the presence of that drug.
forensic urine drug testing (FUDT)
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
Testing that can be used to determine drug use in individuals through the use of a urine sample, often for parole cases and employment screens. Testing is
generally for opiates, amphetamines, cannabis, phencyclidine, and cocaine.
gases
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
Substances that are vapors naturally or at low temperatures, including CO and inhalants.
headspace gas chromatography
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A form of gas chromatography that uses as the injected sample air collected from above a liquid that contains the compound of interest, such as air taken from a
sealed vessel that contained blood suspected of having alcohol in it.
heavy metals
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
Elements that are toxic when ingested, such as mercury, lead, arsenic, and thallium.
human performance
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
The ability of a person to complete tasks under various conditions. In toxicology, this usually refers to impairment caused by ingestion of drugs or alcohol.
immunoassay tests
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A class of tests that relies on a reaction between antigens and antibodies to produce a result.
internal standard
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A compound that is not likely to be found in a sample, which can be added during analysis to help standardize results for quantitation and identi ication of a drug.
metabolism
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
The process by which the body breaks down drugs and other materials to enable their elimination from the body in the urine or feces.
metabolite
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
The breakdown product of a drug once it has been metabolized by the body.
negative control
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
A standard sample that does not contain a drug and is used by the analyst to make sure that the test being used is working and will show a negative result when
the sample does not contain the drug being tested for.
NIDA­5
(http://content.thuzelearning.com/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/Gaensslen.5453.18.1/sections/cover/books/G
The original ive classes of drugs of abuse that were screened for in urine drug testing: amphetamin…