Forensic Spotlight

Toxicology Evidence

By Madeline Montgomery
Stock image of a doctor and her patient in an office.


The Forensic Spotlight is a new department in the FBI Law Enforcement Bulletin (LEB) that highlights current and noteworthy developments in the forensic sciences. Articles in the Forensic Spotlight focus on topics such as fingerprinting, ballistics, toxicology, paint analysis, document validity, and other laboratory-based technology used in crime solving. Laboratories willing to share new and interesting information in the various fields of forensic science can submit their articles to the LEB at for review and possible publication in the Forensic Spotlight.

Two college freshmen arrive at a local emergency room one Sunday morning. Looking terrified, the young ladies approach the admissions desk, and one informs the triage nurse that her friend was raped. The nurse immediately takes them to a private room and pages the on-call forensic nurse. When the forensic nurse arrives and begins talking to the victim, she notices that the young woman has fragmented memories of the previous night. The nurse suspects that the girl was drugged. She asks the young lady if she is willing to undergo a rape examination that includes the collection of blood and urine for toxicology screening. The young woman is hesitant because she is underage and was drinking the night before, but she agrees to the evidence collection. The forensic nurse submits the specimens to the local crime laboratory, along with the rest of the rape kit, for forensic testing.

This scenario describes a typical drug-facilitated sexual assault (DFSA) case. DFSA cases occur when a victim is under the influence of alcohol or other drugs. Due to the effects of the drugs, the victim is unable to resist sexual advances. A DFSA can happen when an individual has been slipped a drug without consent, has voluntarily consumed alcohol or other drugs, or has ingested a combination of both. Despite the frequency of situations, such as this, the appropriate toxicology evidence is not always collected. This could be because the victim does not report the crime—in a timely manner or at all—or chooses not to donate toxicology specimens, possibly for fear of being identified as a drug user. In other cases, due to hospital policy or local laws, hospital personnel must wait for a victim to become sober and consent to evidence collection. Sometimes in a DFSA case, individuals who encounter the victim do not recognize the importance of collecting toxicology evidence.

Certain signs and symptoms indicate that a victim may have been impaired during an assault. In these cases toxicology evidence should be collected.

  1. Memory loss—a total loss of a period of time (blackout) or difficulty piecing segments of time back together (fragmented memories)
  2. Loss of consciousness
  3. A hangover that is inconsistent with the recalled amount of alcohol or other drugs the individual knowingly consumed
  4. Dizziness or light-headedness
  5. Nausea or vomiting
  6. Feeling or appearing more drunk than appropriate for the level of alcohol consumed

Toxicology specimens should be obtained within certain time periods and under specific conditions. Urine always should be collected if 120 hours (5 days) or less have passed since the alleged assault. In addition to urine, blood should be drawn if it has been less than 24 hours since the incident. Hair can be submitted if it is too late to take blood or urine specimens. It is best to wait at least 1 month after the alleged assault, and collect hair as directed by the lab that will be performing the forensic testing. Not all forensic laboratories offer testing of hair for drugs. Individuals must contact the lab for guidance prior to submitting hair specimens.

Toxicology evidence should be sent to a forensic laboratory that has experience analyzing suspected DFSA cases. Most hospital laboratory screening is not appropriate for DFSA testing, and not all forensic toxicology laboratories are experienced in DFSA analysis. If the local laboratory is not able to perform toxicology testing in DFSA cases, the FBI Laboratory can assist. FBI laboratory services are free of charge for law enforcement agencies if local services are not available. There is no fee for expert testimony in criminal cases where a proficient FBI professional has performed testing. The turnaround time for toxicology testing at the FBI Laboratory for DFSA cases typically is less than 60 days.

Ms. Montgomery is the supervisor of toxicology at the FBI Laboratory in Quantico, Virginia. Individuals should contact the FBI Laboratory Chemistry Unit at (703) 632-8441 for additional information.