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Considerations for Optimal Timeframes for DNA Forensic Evidence Collection from Sexual Assault Cases

NCJ Number
Date Published
August 2021
3 pages

Building on recommendations developed by the U.S. Justice Department’s Bureau of Justice Assistance’s (BJA’s) National Sexual Assault Kit Initiative (SAKI) about best and preferred investigative practices for sexual assault cases, this guide addresses the collection of sexual assault evidence samples as soon as possible, optimal timeframes for evidence collection, and ways to support victims in decisions about evidence collection.


A review of timing-related considerations in sexual assault investigations addresses the following issues: victim preferences; victim memory of the features of the sexual assault; the investigative value of information and evidence collected from the victim during a sexual assault nurse examiner’s examination; and the resources available for sexual assault evidence collection. A table is provided to indicate the optimal sample-collection timeframes for victims who are still alive. Another section of this report addresses issues in partnering with victims to establish expectations. A list provides agencies with considerations for review prior to creating policy on the collection time for DNA forensic evidence. A concluding comment notes that the SAKI Training and Technical Assistance Team recommends that agencies consider 5 days as the optimal collection time when creating policy related to collection of evidence for the sexual assault kit (SAK). Victims should be informed of the reduced possibility of obtaining DNA forensic evidence after 5 days. Frequently asked questions for DNA forensic evidence collection are addressed. 4 references


Date Published: August 20, 2021