Condom Trace Evidence: A New Factor in Sexual Assault Investigations

Examination of Victims

Victims of sexual assault may feel ashamed and may not want to disclose some of the more personal details of the crime. Although investigators should make every effort to spare victims any unnecessary discomfort or embarrassment, they must ensure a thorough investigation. This may mean asking victims embarrassing questions and then making sure that medical examiners obtain samples from any area of the victim’s body where evidence may exist, including the vagina, the mouth, and the anus.

In addition to collecting traces from inside the victim’s vagina, medical examiners should swab the external genitalia. Traces of water-soluble condom lubricants may have been absorbed or lost, and as a result, any traces found internally may be at a very low level. Thus, if the victim has not showered or bathed, swabs may recover undiluted traces present on the external genitalia. Although these traces would not indicate penetration, they at least would support the victim’s assertion that sexual contact took place. Moistening each swab with a few drops of isopropyl alcohol helps recover traces from external genitalia.

To create control swabs for the forensic laboratory, investigators should moisten two unused swabs, allow them to air-dry, and then package them with the evidence. Examining these control swabs will confirm that any traces found on the victim did not come from the cotton swabs or the alcohol. At the lab, forensic experts first examine the victim’s swabs. If these swabs are negative for seminal fluids but show traces of condom evidence, examiners would then look for the same traces on the suspect’s swabs.

Examination of Suspects

If investigators identify and arrest a suspect only a few hours after the alleged assault, medical personnel should examine him promptly. If a suspect has not washed his penis, identifiable traces (either from a condom or from the victim) may be present. Examiners should moisten two swabs with two drops of isopropyl alcohol, then wipe the penis from the base to the tip. As they did when collecting evidence from the victim, examiners should prepare two control swabs.


With the Victim

In addition to providing general information about the crime, victims may be able to supply valuable details about the condom and its wrapper. They may recall the brand itself or other important details, including the condom’s color, shape, texture, odor, taste, and lubrication. After obtaining facts about the condom, investigators should ask victims about their sexual and hygienic habits, which might account for traces not attributable to the crime.

A comprehensive interview would include the following questions:

  • Has the victim recently engaged in consensual sex?
  • If so, was a condom used? A vaginal lubricant? What brands?
  • Does the victim use any external or internal vaginal products (anti-itch medications, deodorants, douches, suppositories, etc.)?
  • If so, what brands?

These questions assume an adult female victim. Investigators must modify the interview to accommodate male or child sexual assault victims.

With the Suspect(s)

Investigators also should question the suspect about the condom. A cooperative, honest suspect can reveal the brand, tell where he purchased it, and describe how and where he disposed of both the condom and the empty packet. An uncooperative or deceitful suspect may claim he does not know or cannot remember, or he may name a popular brand but will not be able to describe the condom or the packet in detail.

Legal Considerations

When investigators know or suspect that a sexual offender used a condom, they must remember to list condoms on the warrant obtained to search the suspect’s possessions. The search of a suspect’s home may reveal intact condom packets, but if investigators have not listed condoms on the search warrant, they will not be able to seize this valuable evidence.


When sexual assailants wear condoms to commit their crimes, they attempt to protect themselves from disease and apprehension at the same time. Although these crimes become more difficult to solve, investigators should not overlook the evidentiary potential of condom traces. By considering the possibility of condom use while processing the crime scene, supervising medical examinations, and conducting interviews, investigators can ensure that this valuable evidence receives the attention it deserves.


  1. In 80 sexual assault cases submitted to the Forensic Laboratory of the Las Vegas Metropolitan Police Department between 9/10/93 and 12/3/93, 19 victims reported that the assailant or one of several assailants had worn a condom during the assault or that a consensual sexual partner had used a condom within 72 hours preceding the incident. Eight additional victims believed that their assailant might have used a condom. Terry L. Cook, criminalist, Forensic Laboratory, Las Vegas Metropolitan Police Department, telephone conversation with the author, December 6, 1993.
  2. R.D. Blackledge and L.R. Cabiness, “Examination for Petroleum Based Lubricants in Evidence from Rapes and Sodomies,” Journal of Forensic Sciences, 28, 1983, 451-462.
  3. R.D. Blackledge, “Collection and Identification Guidelines for Traces from Latex Condoms in Sexual Assault Cases,” Crime Laboratory Digest, 21, 1994, 57-61.

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