Forensic Toxicology in Drug-Facilitated Sexual Assault

DFSA

Drug-Facilitated Sexual Assault - Use of a chemical agent to procure sexual contact.

Sexual Assault

Forced, coerced or pressured sexual contact.

Acquaintance Rape

Nonconsensual sexual contact with someone who is known to you.

Date Rape

Nonconsensual sex takes place between two people in a relationship.

Involuntary Injestion

Consumption of food/drink that has been involuntarily 'spiked' with a drug.

Voluntary/Involuntary Ingestion

Willingly consumed untainted food/drink, followed by consumption of food/drink that has been 'spiked' with a drug.

Freely Consumed Voluntary Ingestion

Freely, and without coercion, consumed food/drink/drugs with known incapacitating effects. No substance surreptitiously administered to the victim

Common Elements of DFSA

• Non-threatening environment

• Consumption of tainted food/drink

• 'curtain comes down' on the victims awareness 

• loss of consciousness and memory 

• Moved to another location

• Unsure if sexually assaulted or identify signs they have been 

Signs of DFSA

• Recalls having drink, cannot recall what happened after

• Suspects someone had sex with them

• Feels more intoxicated than their usual response to the same quantity of alcohol

• Wakes up feeling hungover, cannot remember a period of time

Symptoms of DFSA

Confusion, Dizziness, Drowsiness, Memory loss, Slurred speech, unusual behaviour, impaired judgement, reduced inhibitions, physical incapacitation, out of body experience, paralysis.

Response to DFSA 

Victim never blames - regardless of alcohol or drug abuse 

Consenting to drink is not consenting to sex

Unintended consequences - criminal charges (underage drinking, consensual illegal drug use)

Challenges Surrounding the Investigation

• Lack of clarity from victim - no clear narrative 

• Drugs used - different detection windows 

• Reporting the crime - drugs left system, evidence less reliable 

• Collection of evidence - poor handling

• Laboratory methodologies - sensitivity levels, no national standards for testing 

• Lack of experience, lack of recognition - misclassified as sexual assault or voluntary intoxication - missed opportunities 

Drugs Reportedly Used to Commit DFA

Ethanol - most common

Rapidly acting CNS depressants

Ohters: GHB, Benzodiazepines, Ketamine, Opiates, Flunitrazepam, Antihistamines, Clonazepam, Hallucinogens, Lorazepam, Antidepressants, Alprazolam, Chloral Hydrate, Triazolam, Muscle Relaxants, Chlordiazepoxide, Clonidine, Diazepam, Yohimbine, Temazepam, Zolpidem, Barbiturates.

Ethanol Detection Windows

Blood 8-10 hours, Urine 24 hours

Benzodiazepines and their detection window 

Tablets, some change colour when dissolved

Diazepam, flunitrazepam, valium etc

Blood 48hrs, Urine 48-72hrs 

GHB and detection windows

Colourless liquid or white powder, bitter. Detectable: Up to <8h in blood, 10-12 hrs in urine, effects: 15 minutes, relaxation, euphoria, reduced inhibitions for 3-4hrs

GBL and detection windows 

Tablets, bitter tasting and strong. Effects from 30-40 minutes 

Detection: Blood 24hrs urine 6 hrs

Ketamine and detection windows

White powder or clear liquid, Blood: 4-10, Urine 12-24

Laboratory techniques 

Urine: UV-Vis, GC-FID, GC-MS

If volatile - headspace or SPME

Blood: UV-Vis, GC-FID, GC-MS

Hair: GC-MS, LC-MS

If ethanol not detected - detect metabolites by LCMS

Interpreting Results

Blood: Positive Result = Good indicator of recent exposure, Negative Result = No exposure or collected too late.

Urine: Positive = Good indicator of exposure within the last few days 

Negative= No exposure or collected too late 

Fate of Drugs in the Body

Includes distribution, absorption, excretion, and biotransformation (metabolism). - becomes harder to find - harder to be accurate