We report the case of a suspect (Suspect-3) who was convicted (and later exonerated) of participating in the multiple-attacker rape of two women. The forensic evidence against him was his inclusion in a 17-marker Y-STR mixture isolated from semen on one victim’s clothing. The DNA inclusion produced a match statistic with a combined probability of inclusion of 1 in 741, and a Likelihood Ratio of 3296. While the defense team was told that Suspect-3 was included in the semen DNA mixture, they were not told that all of the Y-STR alleles could also be explained by just the other two accused attackers’ haplotypes. Suspect-3 was subsequently freed after the Taiwan Association for Innocence requested re-examination of the incriminating mixed DNA sample. The Criminal Investigation Bureau was then able to exclude him using an extended set of Y-STR markers (23 loci), leading to his exoneration.
This is an author-produced, peer-reviewed version of this article. © 2017, Elsevier. Licensed under the Creative Commons Attribution-NonCommerical- No Deravatives 4.0 license. http://creativecommons.org/licenses/by-nc-nd/4.0/. The final, definitive version of this document can be found online at Forensic Science International: Genetics, doi: 10.1016/j.fsigen.2017.08.004
Hampikian, Greg; Peri, Gianluca; Lo, Shih-Shiang; Chin, Mon-Hwa; and Liu, Kuo-Lan. (2017). "Case Report: Coincidental Inclusion in a 17-Locus Y-STR Mixture, Wrongful Conviction and Exoneration". Forensic Science International: Genetics, 31, 1-4. https://doi.org/10.1016/j.fsigen.2017.08.004