Stefan Rose, M.D.: A Forensic Update on Date Rape Drugs (Drug Facilitated Sexual Assault)

Date rape drugs are those substances that impair a person’s ability to give consent to sexual activity or incapacitate the person so that they may not resist a sexual assault regardless of ability to give consent.

A person (usually a female but sometimes a male) may become voluntarily intoxicated or involuntarily intoxicated but the end result is the same. The drug (or drugs) effect is to cause a change in the mental status of the person so that they are impaired to make the consensual decision regarding sexual activity.

Another effect may be to incapacitate a person’s ability to resist sexual advances or sexual assault by impairing their neurologic motor functions such as stance, balance, and gait rendering the person unable to locomote away from the perpetrator or physically resist them. 

Many substances can cause both effects at the same time, notably ethanol, benzodiazepines and opioids.

The list of possible date rape drugs is large. See the list shown below. Ethanol, benzodiazepines, opioids and THC (tetrahydrocannabinol) are commonly detected in the blood and urine samples of date rape victim investigations. ¹

The investigation of a suspected sexual assault case may begin with the complaint of a victim or a member of the victim’s family or friend of the victim.

The investigation of a date rape case has been described by the Department of Justice in their document “A National Protocol for Sexual Assault Medical Forensic Examinations” ²

Key elements of the forensic examination of the sexual assault victim include: ²

1. Timeliness
   1. For best results in collecting evidence and treatment of the victim the forensic examination should begin as soon as possible. Barriers exist that may delay the forensic examination (injuries to the victim requiring medical treatment, remote occurrence of the assault such as a cruise ship, delay in reporting due to prolonged effects a drug or other substance). In spite of delays the forensic examination should proceed as soon as possible after the assault.

2. Confidentiality and privacy
   1. Everybody involved in the examination should be trained and aware of confidentiality and privacy issues while conducting the investigation. Proper documentation describing the investigation should be kept with the same security as any criminal case.

3. Chain of custody
   1. The chain of custody should be complete for all documents and evidence collected including interviews, recordings, examinations, tests, and blood, urine and any other samples collected during the investigation.

4. Interview
   1. The person conducting the interview is often a law enforcement professional conducting an interview as part of the investigative criminal process.
   2. A sexual assault examiner” (SAE) may be a health care provider (e.g., a physician, physician assistant, nurse, or nurse practitioner) who has been specially educated and trained to perform a sexual assault exam may also perform a clinical interview as part of the victim history. This interview is different from the law enforcement interview but may be complementary.

5. Clinical examination
   1. A sexual assault examiner  should perform a clinical examination as soon as is practical in an appropriate setting with the necessary resources to perform a complete sexual assault examination. Those resources include:
      1. A copy of the most current exam protocol used by the jurisdiction.
      2. Standard exam room equipment and supplies for a physical assessment and evidentiary pelvic exam.
      3. The needs of patients with physical disabilities should be taken into account.
      4. Comfort supplies for patients, even if minimal. Suggested items: clean and ideally new replacement clothing, toiletries, food and drink, and a phone or at least easy access to a phone in as private a location as possible. It is also important during the exam process to help patients obtain items they request related to their spiritual healing.
      5.  It may be useful for facilities to have items on hand that are commonly requested in that jurisdiction (e.g., things that are used for local tribal traditional healing practices) and policies for their use in the facility.
      6. Sexual assault evidence collection kits and related supplies. (See B.4. Sexual Assault Evidence Collection Kit for information on minimal kit contents.) Related supplies might include tweezers, tape, nail clippers and scrapers, scissors, dental floss, collection paper, saline solution or distilled water, extra swabs, slides, containers, envelopes, paper bags, and pens/pencils.
      7. A method or device to dry evidence. Drying evidence is critical to preventing the growth of mold and bacteria that can destroy an evidentiary sample. With any drying method or device used, ensure minimal contamination of evidence, and maintain the chain of custody. The kit’s design can also aid in the drying process (e.g., by providing clear instructions and supplies to allow drying to occur).
      8. A camera and related supplies (using the most up-to-date technology possible) for forensic photography during initial and follow-up examinations. Related supplies might include film, batteries, a flash, and an inch scale or ruler for size reference. (Also see C.5. Photography.)
      9. Testing and treatment supplies needed to evaluate and care for patients medically (follow exam facility policies). Also, testing supplies may be needed for forensic purposes that are not included in the evidence collection kit. For example, supplies for toxicology testing are often not in the kit.
      10. An alternate light source (using the most up-to-date technology possible) can aid in examining patients’ bodies, hair, and clothing. It is used to scan for evidence, such as dried or moist secretions, fluorescent fibers not visible in ambient light, and subtle injury.
      11. While the exam can be done without a light source, it is a relatively inexpensive piece of equipment that is commonly used during exams.
      12. An anoscope may be used in cases involving anal/rectal trauma. This instrument can help in visualizing an anal injury, obtaining reliable rectal swabs (if there is a concern about contamination), and identifying and collecting trace evidence. Many health care facilities have anoscopes available. 
      13. Written materials for patients. 
   2. Steps in the sexual assault examination include the following:
      1. Initial Contact
      2. Triage and Intake
      3. Documentation by Health Care Personnel
      4. The Medical Forensic History
      5. Photography
      6. Exam and Evidence Collection Procedures
      7. Drug-Facilitated Sexual Assault
      8. STI Evaluation and Care
      9. Pregnancy Risk Evaluation and Care
      10. Discharge and Follow-up
      11. Examiner Court Appearances

6. Toxicology investigation of a sexual assault case ²

“Promote training and develop jurisdictional policies. It is essential that examiners and other relevant health care personnel, 911 dispatchers, law enforcement representatives, emergency medical technicians, prosecutors, judges, and advocates receive training and information on drug-facilitated sexual assault. They need to be educated on the use of drugs and alcohol to facilitate sexual assault, screening for drug-facilitated assault, and how to handle situations in which a drug-facilitated sexual assault is suspected. Both agency- specific and multidisciplinary policies should be developed to guide immediate response to a suspected drug-facilitated sexual assault.²³⁴

First responders must recognize that although Rohypnol and gamma hydroxy butyrate (GHB) are widely publicized as the “drugs of choice” in drug-facilitated sexual assault, assailants may use numerous other drugs (including alcohol) to facilitate sexual assault.²³⁵ They must understand the urgency of collecting toxicology samples, if it is medically necessary, or if a drug-facilitated sexual assault is suspected, as well as the importance of obtaining informed consent from patients prior to sample collection. They should also be aware that collection of toxicology samples is typically separate from the sexual assault forensic evidence collection kit, and procedures for toxicology analysis may be different from that of other evidence analysis.

Ideally, the first available urine sample should be collected in suspected drug-facilitated sexual assault cases. Law enforcement agencies and emergency medical services should develop procedures and staff training for collection in cases where patients must urinate before arriving at the exam site. Advocates and other professionals who may have contact with patients prior to their arrival at the exam site should also be educated to provide those who suspect that drugs were used to facilitate the assault with information on how to collect a sample if they cannot wait to urinate until they get to the site.

Plan response to voluntary use of drugs and/or alcohol by patients. It may be revealed during the exam process or through toxicological analysis that patients voluntarily used drugs and/or alcohol just prior to the assault.²³⁶ Voluntary drug and/or alcohol use by patients during this period should not diminish the perceived seriousness of the assault. Law enforcement officers and prosecutors should guard against disqualifying cases in which patients voluntarily used illegal drugs or illegally used alcohol. Patients should understand that information related to voluntary alcohol or drug use may be used against them in court, but also that in some instances it might be helpful in prosecuting a case (see the following section on explaining procedures). Also, before pursuing charges related to illegal drug or alcohol use by patients, prosecutors should give great weight to the impact that the threat of such charges may have on patients’ willingness to report the sexual assault and be involved in subsequent criminal justice proceedings.

It is important to document patient voluntary use of drugs and alcohol between the time of the assault and the exam. Some patients may self-medicate to cope with post assault trauma and require immediate medical treatment. In addition, ingestion of drugs and/or alcohol during this period may affect the quality of evidence and impede patients’ ability to make informed decisions about treatment and evidence collection.

Be clear about the circumstances in which toxicology testing may be indicated.²³⁷ Routine toxicology testing is not recommended. However, in any of the following situations, the collection of a urine and/or blood sample may be indicated:²³⁸

• If a patient’s medical condition appears to warrant toxicology screening for optimal care (e.g., the patient presents with drowsiness, fatigue, light-headedness, dizziness, decreased blood pressure, memory loss, impaired motor skills, or severe intoxication);
• If a patient or accompanying persons (e.g., family member, friend, or law enforcement representative) states the patient was or may have been drugged; and/or
• If a patient suspects drug involvement because of a lack of recollection of event(s).²³⁹

Patients should be questioned about involuntary drug/alcohol use only if determined to be medically necessary or if there is a suspicion the assault was drug-facilitated.

Toxicology testing procedures should be explained to patients. Seek informed consent from patients to collect toxicology samples. Patients should understand the following before agreeing to toxicology testing:²⁴⁰

• The purposes of toxicology testing and the scope of confidentiality of results;²⁴¹
• The ability to detect and identify drugs and alcohol depends on collection of urine and/or blood within a limited time period following ingestion;
• There is no guarantee that testing will reveal that drugs were used to facilitate the assault;
• Testing may or may not be limited to drugs commonly used to facilitate sexual assault²⁴² and may reveal other drugs or alcohol that patients may have ingested voluntarily;
• Whether any follow-up treatment is necessary if testing reveals the presence of drugs used to facilitate sexual assault;²⁴³

Test results showing voluntary use of drugs and/or alcohol may be discoverable by the defense and used to attempt to discredit patients or to question their ability to accurately perceive the events in question (however, these results could also help substantiate that voluntary drug and/or alcohol use sufficiently impaired patients’ consent and prevented legal consent);²⁴⁴

• Whether there is a local prosecution practice of charging sexual assault victims for illegal voluntary drug and/or alcohol use revealed through toxicology screening;
• Failure or refusal to undergo testing when indicated by circumstances as described above may negatively impact the investigation and/or prosecution;²⁴⁵
• When and how they can obtain information on the results from toxicology testing;
• Who will pay for toxicology testing; and
• Whether patients have the opportunity to revoke their consent to toxicology testing.²⁴⁶

Care should be taken when providing the above information to patients. In particular, they may need to hear repeatedly from examiners that voluntary use of drugs and/or alcohol, if any, does not reduce the seriousness of the assault. Under no circumstances should the medical forensic exam and treatment be conditioned upon patient consent to toxicology testing.

Toxicology samples should be collected as soon as possible after a suspected drug-facilitated case is identified and informed consent is obtained, even if patients are undecided about reporting to law enforcement. The length of time that drugs used for drug-facilitated assault remain in urine or blood depends on a number of variables (e.g., the type and amount of drug ingested, patients’ body size and rate of metabolism, whether patients had a full stomach, and whether they previously urinated).²⁴⁷ Urine allows for a longer window of detection of drugs commonly used in these cases than does blood.²⁴⁸ The sooner a urine specimen is obtained after the assault, the greater the chances of detecting drugs that are quickly eliminated from the body.²⁴⁹

Immediately collect a urine sample when appropriate. If patients may have ingested a drug used for facilitating sexual assault within 96 hours prior to the exam, a urine specimen of at least 30 milliliters but preferably 100 milliliters (about 3 ounces) should be collected²⁵⁰ in a clean plastic or glass container (follow jurisdictional policy). The urine sample does not have to be a clean catch (e.g., blood in the urine will not compromise test results). If patients cannot wait to urinate until their arrival at the exam facility, first responders should ask them to provide a sample and bring it to the facility, documenting the chain of custody. It is suggested that law enforcement officers and emergency medical technicians keep toxicology screening kits readily available, according to agency policy.

Ideally, patients should not urinate until after evidence is collected. However, the number of times that patients urinated prior to collection of the sample should be documented.

Collect a blood sample when appropriate. If ingestion of drugs used to facilitate sexual assault may have occurred within 24 hours prior to the exam, a blood sample of at least 20 milliliters should be collected in a gray-top tube (contains preservatives sodium fluoride and potassium oxalate²⁵¹) according to jurisdictional policy. A blood sample taken within this time period may pinpoint the time when drugs were ingested.²⁵² If a blood sample is collected for toxicology screening, it should be accompanied by a urine sample. If blood alcohol determination is needed, collect blood within 24 hours of alcohol ingestion, according to jurisdictional policy. (If blood has already been taken due to suspected drug ingestion, that sample can be used to determine blood-alcohol level. An additional sample usually is not needed.)

Occasionally, patients of drug-facilitated sexual assault vomit. The analysis of the vomit may also be useful to an investigation.²⁵³ Collect and preserve according to jurisdictional policy.

Package samples as appropriate. Package each toxicology sample according to the policy of the lab doing the analysis, place in envelope, label, seal, and initial the seal.

Identify toxicology laboratories. Exam facility laboratories should not analyze toxicology samples in suspected drug-facilitated sexual assault cases. Instead, involved criminal justice agencies should identify forensic laboratories that can analyze these toxicology samples (they should have the capacity to detect drugs in very small qualities).²⁵⁴ Information about these labs (e.g., contact information, evidence collection and packaging procedures, and transfer procedures) should be provided to law enforcement representatives investigating these cases, exam facilities, and examiner programs.

If toxicology tests are needed purely for the medical evaluation of patients, the exam facility lab typically performs these tests. Lab results are recorded in patients’ medical records, according to facility policy. If toxicology samples are needed for both clinical and forensic purposes, one sample can be collected for immediate evaluation by the exam facility lab and another for analysis by the identified forensic lab. Take samples at the same time to avoid more discomfort to patients than is necessary.

Preserve evidence and maintain the chain of custody. Involved health care personnel should be aware of the toxicology lab’s requirements on collection, packaging, labeling, storage, handling, transportation, and delivery of specimens.²⁵⁵ Policies should be in place for storage of these samples when patients are undecided about reporting. As with any forensic evidence, the chain of custody must be maintained.

Refer to the current Forensic Toxicology Laboratory Guidelines by the Society of Forensic Toxicologists, Inc., and the American Academy of Forensic Sciences for detailed guidance on proper collection, labeling, handling, submission, and analysis of toxicology samples.²⁵⁶ “

The comprehensive investigation of a sexual assault case requires both proper resources and specially trained health care professionals to perform a history, physical examination and collect the appropriate evidence including toxicology samples. Working in conjunction with investigating law enforcement professionals the sexual assault examiner can provide aid and comfort to the victim as well as collecting forensic evidence in a secure manner to protect the forensic integrity of the investigation.

The toxicological analysis may be very helpful to the law enforcement investigation depending on the results and the specific facts of the case.

References

1. Fiorentin, T.R., “Toxicological findings in 1000 cases of suspected drug facilitated sexual assault in the United States”, Journal of Forensic and Legal Medicine, Volume 71, April 2020, Pages 56-64
2. U.S. Department of Justice “A National Protocol for Sexual Assault Medical Forensic Examinations”, September 2004

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