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Beyond DNA - The Role of Physical Evidence in Sexual Assault Investigations

NCJ Number
Date Published
January 2019
6 pages

This first of a three-part series on the role of physical evidence beyond DNA in sexual assault investigations highlights the role of such physical evidence and identifies the types of such evidence in these investigations.


The introductory section notes that although DNA evidence in a sexual assault case is valuable, it is not always present or probative in every sexual assault case. Even in cases where a DNA profile is present, it may not meet the quality standards required to be uploaded into CODIS; 38 percent of DNA profiles were found to be ineligible for CODIS matching; and even in cases where a DNA profile is CODIS-eligible, a hit occurs in only about half of the cases. Physical evidence collection, submission, and analysis can be an effective and essential means of reconstructing some of the events in a sexual assault. Probative physical evidence may include physical injuries such as bruising and lacerations; toxicology; digital evidence, such as text messages, emails, and cellphone records; the identification of biological fluids, such as saliva and semen; impression evidence (e.g., fingerprints and shoeprints); trace evidence (e.g., hairs and fibers); and other physical evidence such as bedding and clothing. The effective collection of physical evidence from the victim, the suspect, or wearable items should be conducted by specially trained personnel, such as sexual assault nurse examiners (SANEs), who are trained to collect physical evidence in sexual assault cases and follow correct procedures for preserving and transferring such evidence for analysis. 25 resources

Date Published: January 1, 2019