Toxicology a part of forensic Drug Recognition expert

1. Role of Toxicological Findings

2. Contents
•Introduction
•Toxicology- a part of forensic
•Role of toxicological Findings
•Drug Recognition Expert

3. Introduction
• Toxicologist:
Detect and identify the
presence of drugs and poisons in body
fluids, tissues, and organs.
• Toxicology is the combination of
chemistry and physiology that deals
with drugs, poisons, and other toxic
substances and how these
substances effect living organisms.

4. Drugs and toxic chemicals span
a high range from alcohol to
heroin and crack cocaine and
on to killers, including arsenic
and cyanide that are used only
as tool of aggression or suicide.

5. It's all in the dose
•The degree of toxicity of any
substance depends on how much
enters your body and over what
period of time it does so.

6. Toxicology Plays a part in forensics at three
levels:
1. A criminalist may be asked to see if a persons
behavior has been influenced by a drug.
2. A forensic team may examine evidence to see
whether a suspect has been manufacuring
illicit(forbidden by law, rules, or custom)
compounds.
3. Forensic experts will look for evidence that a toxic
substance has killed a person.

7. Significant of Toxicological Findings
•Once a drug is found and identified, the
toxicologist assesses its influence on the
behavior of the individual.
•Need to take into account a potentially
lethal(sufficient to cause death) drug
combination.

8. •Toxicologists can determine:
1. What was present in a victim's (or a living
person)
2. How much was present
3. The probable state of the person's
behavior based on the known substance.
4. If the use was prolonged or sudden

9. •Deceased person- check drug levels in
various body organs and tissues to
provide additional information.

10. •The analyst must understand the effect of a
particular substance, what possible interactions it
may have with other drugs or natural disease
processes, and an understanding of what happens
to toxins in the body over a period of time.

11. •Coroners and medical examiners are
responsible for determining the cause and
manner of death, and they use all aspects of
the case to do so, including circumstances,
autopsy findings, crime scene details and
any information from laboratory testing.

12. •Biological samples can be unstable and can change
or further degrade after they are collected for
testing.
•Factors that can alter readings of drug
concentration include quality of specimen due to
decomposition, redistribution of drugs from other
tissues, contamination or degradation of the drug
after death.

13. •The effects of the concentration vary from
person to person, and all factors must be
considered when determining whether a
substance found in the system can be
identified are causing or contributing to
behavioural changes of death.

14. •Once the drug is extracted and identified, the
toxicologist may be required to provide an opinion on
the drug’s effect on an individual’s natural
performance or physical state.
•For many drugs, blood concentration levels are readily
determined and can be used to estimate the
pharmacological effects of the drug on the individual.
•Eg: Detecting Drugs in Hair, Nondrug Poisons

15. • The concentration of a drug in urine is a poor indicator of
how extensively an individual’s state is influenced by the
drug.
• Drugs can be found in the urine 1-3 days after being taken
• Before drawing conclusions about drug-induced behavior,
the analyst must consider other factors including age,
health, and tolerance.
• Often, when dealing with a living person, the toxicologist
has the added benefit of knowing what a police officer may
have observed about an individual’s behavior and motor
skills.

16. DRUG RECOGNITION
EXPERT

17. DRUG RECOGNITION EXPERT (DRE)
• A Drug Recognition
Expert (DRE) is a law
enforcement officer
trained to identify people
whose driving is impaired
by drugs other than, or in
addition to, alcohol .

18. • In the early 1970, Los Angeles Police Department
developed clinical and psychophysical examinations
that a trained police officer could use to identify and
differentiate between types of drug impairment.
• This program has evolved into a national program to
train police as DREs.
• Normally, a 3-5 month training program is required to
certify an officer as a DRE.
• The DRE program incorporates standardized methods
for examining suspects to determine whether they have
taken one or more drugs.

19. •To ensure that each subject has been tested in
a routine fashion, each DRE must complete a
standard Drug Influence Evaluation form.
•The DRE program usually cannot determine
which specific drug was ingested.
•Hence, it is the production of reliable data
from both the DRE and the forensic
toxicologist that is required to prove drug
intoxication.

20. A DIE involves the following 12 steps:
• Breath Alcohol Test: The arresting officer reviews the subject's breath alcohol
concentration (BrAC) test results and determines if the subject's apparent
impairment is consistent with the subject's BrAC. If so, the officer will not
normally call a DRE. If the impairment is not explained by the BrAC, the
officer requests a DRE evaluation.
• Interview of the Arresting Officer
• Preliminary Examination and First Pulse
• Eye Examinations
• Divided Attention Psychophysical Tests

21. • Vital Signs and Second Pulse
• Dark Room Examinations
• Examination for Muscle Tone
• Check for Injection Sites and Third Pulse
• Subject's Statements and Other Observations
• Analysis and Opinions of the Evaluator
• Toxicological Examination : After completing the evaluation, the DRE
normally requests a urine, blood and/or saliva sample from the subject
for a toxicology lab analysis.

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