Since the 1990s, reports of drug-facilitated crimes have continued to increase. Drugs may be used to render a victim incapacitated so that an assailant can commit sexual assault, robbery, or other illicit crimes. The amnestic effects of many of the drugs used often allow for little or no recollection of the events, making investigation and prosecution of the suspect more difficult.

1. High-risk populations include single women, unsuspecting travelers new to an area, and those without companions. Drug administration may occur in a bar, club, or on public transportation when the victim leaves a drink unattended or accepts an opened bottle. In one series of self-reported cases, half the victims reported meeting the assailant in a public place, and more than 70% of the victims knew the assailant (eg, a friend or colleague).
2. Drugs used. Contrary to the popular belief that specific “date rape drugs” are involved in these crimes, a variety of substances with amnestic or central nervous system (CNS) depressant effects can be used to facilitate assault, including opioids, anesthetics, benzodiazepines, other sedative-hypnotic drugs, skeletal muscle relaxants, anticholinergics, hallucinogens, clonidine and related central alpha-adrenergic agonists, aromatic solvents, and ethanol (Table I-44).
   1. Note that many of these drugs are also commonly used to “get high” and may have been self-administered by the victim for this purpose.
   2. Benzodiazepines are often selected for their anterograde amnestic effect, which is related to, but distinct from sedation. The strength of the amnestic effects can be predicted to increase with the dose, rapidity of onset, lipophilic character, and slow redistribution from the CNS.
3. Routes of surreptitious drug administration
   1. Drink: tablet, ice, liquid in eyedropper.
   2. Smoke: applied to a cigarette or joint.
   3. Ingestion: brownie, gelatin, fruit, other food.
   4. Vaginal syringe: drug in contraceptive gel.
   5. Represented as another drug.
4. Clinical evaluation. If the victims present early after the assault, they may still be under the influence of the drug and may appear inappropriately disinhibited or relaxed for the situation. Unfortunately, victims often present many hours, days, or even weeks after the assault, making the collection of physical and biochemical evidence much more difficult. Determining the time course of drug effects with estimation of last memory and first recall may provide useful information to investigators.
   1. Use open-ended questions to avoid suggesting symptoms to a victim who may be trying to fill in a lapse in memory.
   2. Perform a thorough examination and maintain the legal chain of custody for any specimens obtained.
5. Laboratory. Timing of laboratory analysis may be crucial, as elimination rates of commonly used sedative and amnestic drugs vary, and some may be extremely short. Immediate collection of toxicology specimens is important to avoid loss of evidence. For a service that deals in assaults or sexual abuse, it is important to communicate in advance with the laboratory so that it is clearly understood what type of testing will be performed; the laboratory can then develop a testing strategy (what tests to use, the sequence of tests and confirmations, and the level of sensitivity and specificity). Such a service should ideally be part of law enforcement. Note that most clinical laboratories do not have the ability to document the chain of custody often needed in criminal proceedings.
   1. Blood. Collect a 10- to 30-mL specimen as soon as possible and within 24 hours of the alleged assault. Have the specimen centrifuged and the plasma or serum frozen for future analysis. Pharmacokinetic evaluation of multiple blood levels may allow estimations of time course, level of consciousness, and amount ingested.
   2. Urine. Collect a 100-mL specimen if it is within 72 hours of suspected ingestion and freeze for analysis. (Note: Flunitrazepam [Rohypnol] may be detected for up to 96 hours.)
   3. Hair. Collect four strands of about 100 hairs each from the vertex posterior close to the scalp 4-5 weeks after the offense and mark the root end. Hair analysis may become a useful complement to conventional blood and urine drug analysis. Currently, however, few forensic laboratories perform hair analysis, and legally defensible methods and values are needed for a single drug exposure.
   4. Analysis (see Table I-44). Hospital laboratories doing routine toxicology testing have different testing strategies and levels of detection and may not detect drugs used to facilitate assault. Rapid toxicology screens (eg, “drugs of abuse” screens) will not detect all commonly available benzodiazepines or other CNS depressants (eg, ketamine, gamma-hydroxybutyrate, carisoprodol) commonly used in drug facilitated assault. It may be necessary to contract for special services through national reference laboratories, state laboratories, or a local medical examiner's office to identify uncommon drugs and to detect very low levels of drugs that remain in cases of late presentation.
6. Treatment of the intoxication is based on the clinical effects of the drug(s) involved. The assessment and treatment of effects related to individual drugs are detailed in Section II of this book. In addition, victims often need psychological support and counseling and the involvement of law enforcement authorities. If the assault involves a minor, state law generally mandates reporting to child protection services and law enforcement officials.