Forensic Toxicology

1. Dr. Sarah Kerrigan Director, Forensic Science Program, SHSU Laboratory Director, SHSU Regional Crime Lab The Texas Criminal Justice Integrity Unit & The Texas Forensic Science Commission Joint Conference on Forensic Science Austin, TX June 4-5, 2012 Forensic Toxicology

2. Trends and Challenges • Analytical challenges • Alcohol vs. drug toxicology issues • Laboratory service challenges • Interpretive issues • Scientific testimony challenges

3. Forensic Toxicology Drugs and Poisons in Biological Samples Three sub-disciplines: • Human performance toxicology • Postmortem forensic toxicology • Forensic urine drug testing

4. Forensic Toxicology Drugs and Poisons in Biological Samples Three sub-disciplines: • Human performance toxicology • Postmortem forensic toxicology • Forensic urine drug testing

5. Forensic Toxicology Drugs and Poisons in Biological Samples Three sub-disciplines: • Human performance toxicology • Postmortem forensic toxicology • Forensic urine drug testing

6. Human Performance Toxicology • “Behavioral toxicology” • How drugs influence human performance or behavior • Criminal context - Performance • Impaired driving • Drug-facilitated sexual assault • Other criminal acts while under the influence of a drug • Death investigation

7. Role of the Toxicologist

8. Analytical Challenges? • Why are the results different (lab to lab)? • Why does it take so long for drug toxicology? • When should a sample receive drug testing? • Toxicology of new designer drugs?

9. Toxicology Testing Alcohol • Gas chromatography-Flame Ionization Detection (GC-FID) • Headspace GC • Standardized methodology • Well established and accepted Drugs • Two-step process • Screening (often “immunoassay”) • Confirmation e.g. GC-MS • Many procedures (many drugs) • Well established and accepted

10. Drug Testing – Step IPresumptive Screen • Antibody-based test(immunoassay) • Defined “cutoffs” • Know what these are • Know what drugs are included in the screen • Limited scope • False positives & negatives possible • Not forensically defensible without confirmation

11. Cutoff Concentration POSITIVE e.g.100 ng/mL

12. Cutoff Concentration POSITIVE e.g.100 ng/mL NEGATIVE

13. Drug Testing – Part IIConfirmation • Gas chromatography-mass spectrometry (GC-MS) or similar • Sensitive and specific • Used for qualitative (present) and quantitative testing (how much?) • Forensically defensible • Typically report drugs if they are detectable and/or meet specific criteria • Broad scope (hundreds of drugs) • Requires separation of the drug from the matrix (e.g. blood) • Labor intensive • Expensive

14. Analytical Issues • Methodology widely accepted • Extensive scientific/published literature • Results may vary between laboratories • Sample storage/degradation (biological matrix) • Scope of testing • Cutoffs vary between labs • Equipment/resources at the laboratory • Limits of detection/analytical capabilities • Policies/procedures regarding testing protocols

15. Non-Analytical Issues • Packaging • Chain of custody • Sample storage • Specimen integrity • Collection • Preservation • Services requested by client (non-scientist, i.e. law enforcement)

16. Newer Designer Drug Challenges • Psychedelic Amphetamines (e.g. “Bath Salts”, “Plant Food”) • Synthetic Cannabinoids (e.g. “Spice”)

17. Synthetic Cannabinoids • Sold as an incense “Not for human consumption” • Many are structurally unrelated to THC (tetrahydrocannabinol) • Developed for clinical use initially (CB-2, TBI) • Synthetic cannabinoids that bind to CB-1 receptors produce THC-like effects • Routine testing in controlled substance exhibits • Limited testing in toxicology samples • Limited studies in humans to date • Growing area of concern/research • Large number of substances, complex metabolism

18. Synthetic Cathinones • Novel synthetic amphetamines (cathinone derivatives) • Synthetic derivatives of “Khat” or cathinone • Complex array of adrenergic (stimulant) and hallucinogenic effects • Unregulated until recently (some, not all) • Routine testing in controlled substance exhibits (e.g. pills, powders) • Limited testing in toxicology samples • Relatively few clinical studies • Growing area of concern/research

19. RCL Exhibits (2011) • Synthetic cannabinoids accounted for only 2.7% of all controlled substance findings (N=586). • Synthetic cathinones accounted for only 1.5% of all controlled substance findings (N=323).

20. Why does it take so long? • Complex biological matrices • Isolate the substances prior to analysis • Purification process (extraction) is labor intensive • Specific procedures for isolation each drug or class of drug • Specific procedures for analysis each drug or class of drug • Results subject to technical/administrative review

21. Challenges – Drug Impaired Driving • Drug impaired driving likely underestimated (not all specimens are tested for drugs) • Drug impaired driving may account for 15-50% of impaired driving investigations nationally • Drug impaired driving inherently more complex than alcohol impaired driving

22. Drug vs. Alcohol Impaired Driving Alcohol • Notably the most prevalent drug in impaired driving • Effects, properties and pharmacokinetics are well understood • Produce predictable effects in a dose-dependent manner • Per-se approach Drugs • Prevalence not well understood (likely underestimated) • Many drugs involved (hundreds) • Effects are less predictable • Requires proof of impairment (TX)

23. Toxicology Challenges and Misconceptions in Impaired Driving • What level of [DRUG] is equivalent to a .08? • Any level of [DRUG] indicates impairment • Quantitative vs. Qualitative toxicology reports (Do you need a NUMBER?) • Interpretation based upon lab report in isolation? • Polypharmacy issues – multiple drug/alcohol combinations • Why is the report NEGATIVE? • Cutoffs? • Scope of testing?

24. Are Drugs Important? • 10 million people reported driving after illicit drug use • Drugs (other than alcohol) found in 17.8% fatally injured drivers • Drugs detected in up to 40% of injured drivers requiring medical treatment • Drug use among drivers arrested for motor vehicle offenses is 15-50% • Driving under the influence of drugs (DUID) is highly significant SAMHSA – Substance Abuse and Mental Health Services Administration NHTSA – National Highway Traffic Safety Administration

25. Challenges – Drug Impaired Driving • Inherently more complex (scientifically and legally) than alcohol-related DWI • Fewer studies than for alcohol • Requires toxicologists with specialized training to interpret effects • Drug impairment is determined on a case-by-case basis • Significant number of DWIs - under-reported (testing), under-recognized (training) • Drug use and traffic safety is a significant public health and safety concern for all

26. Statutory Approaches & Scientific Opinions (By State) • Proof of impairment • “incapable of driving safely”, “under the influence”, “impaired to the slightest degree”, “normal use of mental/physical function”, or otherwise affected by a drug • Per-se • Level of substance above which driving is prohibited • Zero Tolerance • Criminal offense to have a specified drug or metabolite in the body while operating a motor vehicle • Combination of SCIENTIFIC and LEGAL variables may influence how we interpret a case

27. Drugs in Impaired Driving

28. Drugs in Impaired Driving • Illicit • Therapeutic • Over-the-counter

29. Drug Impaired Driving • CannabinoidsMarijuana • CNS DepressantsSedative-hypnotics, muscle relaxants, antidepressants, antihistamines, anticonvulsants, antipsychotics, anxiolytics • CNS StimulantsCocaine, methamphetamine, etc • Narcotic AnalgesicsMorphine, codeine, hydrocodone (Vicodin), oxycodone (Oxycontin), methadone, fentanyl etc

30. Drug Prevalence-Montgomery County, TX Drugs • Total of 1,388 drug toxicology findings (drugs reported) in 461 cases • The average number of drugs reported per case was 3 and the range was 0 to 15 • Five most common substances reported: • Hydrocodone (Vicodin) • Cannabis (THC or THCA) • Carisoprodol (Soma) and/or metabolite • Alprazolam (Xanax) • Diazepam and/or metabolite(s) Alcohol • The mean BAC (all requests) was 0.15 g/100mL (N=1,373) • The mean BAC in alcohol-related DWI investigations (BAC>0) was 0.18 g/100mL (N=1,136) • More than one third (34%) of cases submitted by Montgomery County agencies receive drug testing (BAC < 0.1 g/100mL)

31. Laboratory Service Challenges….. • Expensive • Costs increase with increased scope • Multiple drug use is common • Labor intensive • Turnaround times • Policy/Administrative decisions to balance resources, manage backlogs etc

32. SHSU RCL • Average turnaround time (TAT) is 17 days for all cases (N=4,299)

33. Which Drugs Can Impair Driving? • Any drug that can affect the brain’s perception, collection, processing, storage or critical evaluation processes • Any drug that affects communication of the brain’s commands to muscles or organ systems that execute them For the most part, drugs that affect the central nervous system (CNS)

34. Drug Toxicology Challenges • More complex • Often in combination with other drugs and/or alcohol (additive or synergistic effects) • Scientific literature is complex • May require a toxicologist to interpret the results and provide an opinion • These complex issues must be explained to the court using every day language

35. Coordination Perception Reaction Time Drug-Impaired Driving Attention Tracking Judgment

36. Is the driver impaired?

37. Drug Interpretation Issues • Multiple drug use • Tolerance (chronic vs. naïve) • Health • Metabolism • Individual sensitivity/response • Phase of use, withdrawal • Put in context of case e.g. environmental factors, conditions • Other factors (e.g. distraction, injuries, disease) • Typically requires more information than the toxicology report alone

38. Positive Tox Poor Driving Signs and Symptoms

39. Signs and Symptoms: Example - Depressants • Confusion • Poor divided attention • Sedation • Droopy eyelids • Slowed reaction times • Memory effects • HGN • Poor balance • Poor coordination • Unsteadiness • Slurred speech • Disorientation • Low b.p. • Low pulse

41. Documentation DRE • Drug Recognition Expert • Systematic, standardized, post-arrest procedure • 12-step evaluation of behavior, appearance, psychophysical tests, vital signs, eye measurements • DRE provides the court with additional information Other • Observations • Behavior • Signs and symptoms • Mental and physical functions (SFSTs) • Clinical records (EMT, hospital) • Driving behavior

42. Driving BehaviorExample - Depressants • Weaving • Extreme lane of travel • Striking other vehicles • Striking fixed objects • Slow speed • Hit and run • Wrong way driving

43. Hot Tamale Defense • Male, 48y • Vehicle swerves into oncoming traffic • Speech slurred, watery eyes, HGN present • Unsteady on his feet, staggering • Poor SFSTs – falls over during OLS, WAT • Stated that he swerved “To pick up a tamale” • BAC 0.00% • Toxicology: Morphine 0.05 mg/L, Meprobamate 20 mg/LCarisoprodol 2 mg/LOxycodone 0.13 mg/LHydrocodone 0.06 mg/LDiazepam 0.3 mg/LNordiazepam 0.3 mg/LGabapentin, present.

44. Testimony Challenges….. • Choosing the right expert • Appropriate sub-discipline of forensic toxicology • Appropriate level of training/expertise • Training gaps? Need for additional training in forensic toxicology for interpretive testimony….e.g. ”How does this combination of drugs and/or alcohol impair driving?”

45. Recommendations for ToxicologicalInvestigation of Drug Impaired Driving

46. Additional Resources • Drug Toxicology for ProsecutorsAmerican Prosecutors Research Institute, 2004. http://www.ndaa-apri.org/pdf/drug_toxicology_for_prosecutors_04.pdf • Drugs and Human Performance Fact Sheets, DOT HS 809 725, National Highway and Traffic Safety Administration, 2004http://www.nhtsa.gov/people/injury/research/job185drugs/index.htm

47. Contact Information: Dr. Sarah KerriganEmail: sarah.kerrigan@shsu.eduForensic Science Program DirectorSam Houston State University1003 Bowers BlvdHuntsville, TX 77341Laboratory DirectorSHSU Regional Crime Laboratory8301 New Trails Dr.The Woodlands, TX 77381 Tel: 936-294-2501