Victim service providers, crime scene technicians, nurse examiners, and other medical personnel should be aware of important issues involved in identifying, collecting, transporting, and storing DNA evidence. If DNA evidence is not initially identified at the crime scene or on the victim, it may not be collected, or it may become contaminated or degraded.
To assist in collection, victims of sexual assault should not change clothes, shower, or wash any part of their body after the assault. Such evidence as semen, saliva, and skin cells may be found on clothing or bedding, under fingernails, or in the vaginal, anal, or mouth region.
Evidence on or inside a victim's body should be collected by a physician or sexual assault nurse examiner. A medical examination should be conducted immediately after the assault to treat any injuries, test for sexually transmitted diseases, and collect forensic evidence, such as fingernail scrapings and hair. Typically, the vaginal cavity, mouth, anus, or other parts of the body that may have come into contact with the assailant are examined.
The examiner should also take a reference sample of blood or saliva from the victim to serve as a control standard. Reference samples of the victim's head and pubic hair may also be collected if hair analysis is required. A control standard is used to compare known DNA from the victim with that of other DNA evidence found at the crime scene to determine possible suspect(s).
Given the sensitive nature of DNA evidence, victim service providers should always contact crime laboratory personnel or evidence technicians when procedural collection questions arise.
From Understanding DNA Evidence: A Guide for Victim Serice Providers, May 2001, Brochure, National Institute of Justice and Office for Victims of Crime
