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Post-Coital DNA Recovery in Minority Proxy Couples

NCJ Number
Patricia Speck; Erin K. Hanson
Date Published
May 2019
15 pages
This is the Final Summary Report of the findings and methodology of a study that recruited adult minority couples to repeat the validated Post- Coital DNA Recovery (PCDR) protocol to determine the level of DNA recovery at timed intervals post-unprotected coitus in minority couples, using standard STR and enhanced Y-STR methods.
The study also identified the factors that influence post-coital DNA recovery in a comparison of the minority sample with a small sample of new and former non-minority subjects. The PCDR study developed an in vivo study protocol that established a valid scientific foundation for data collected to study expanded post-coital interval in DNA detection and influencing variable. The current study sought to determine whether the first study results are generalizable to minority populations, given a similar influence of menses and hormone birth-control use. The current study re-evaluated incidental findings and determined implications for the criminal justice system. As with the First PCDR study, the current study compared standard Yfiler PlusTM methods to the enhanced YfilerTM Y-STR methods, using 17 identical alleles; it was determined that the standard Yfiler PlusTM method is insufficient in DNA detection from both the cervix and posterior formix at all timed collections (4, 7, 9, and baseline or 10 days). The enhanced YfilerTM YSTR method was unchanged between the first and second studies. This research provides laboratories the evidence to review protocols related to expanded timing of collections to 9 days for all reproductive-age women, regardless of race, triaging to the appropriate scientific method to identify probative samples from the medical forensic clinical setting. 2 tables