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Just Science: Identification: Just a Modified Direct to DNA Approach to Sexual Assault Kit Testing

NCJ Number
Date Published
February 2019
3 pages

This third episode of the Identification season of the National Institute of Justice's (NIJ's) Just Science podcast series is an interview with forensic biologist Caitlin Rogers, who discusses her work in improving the efficiency and accuracy of sexual assault kit (SAK) testing by using a modified direct to DNA approach.


Rogers discusses the methodology and findings of the Colorado Bureau of Investigation's (CBI's) efforts to make the testing of SAK's more efficient and accurate. She describes how the collection of known information on the characteristics of each sexual assault case for which an SAK exists are related to the likelihood of finding male seminal fluid on swabs or slides in the case's SAK. Knowledge about where on or in the victim samples were taken was also found to affect the likelihood of male DNA being found in the SAK. In addition to prioritizing the testing of SAKs based on such information, types of presumptive testing of SAK swabs and slides for male seminal fluid were conducted and compared for accuracy. The swabs found to have a high likelihood of male DNA are then submitted for direct DNA analysis. Rogers reports that this CBI study has yielded a significant increase in the efficiency and accuracy of processing SAKs that yield a male DNA profile.

Date Published: February 1, 2019