Detection of Semen on the Underwear of Females Involved in Sexual Assaults by Using Prostate Specific Antigen (PSA) Kit and its Medicolegal Significance

Abstract

Background: Detection of semen in forensic cases, mostly sexual assault or abuse, is critical for evidence collection. As the number of rape cases is increasing day by day, there is a need for detection of semen, even if present in small quantity, no matter how old the stains are presence of semen is the most reliable marker for the investigation in cases of rape, sodomy, sexual murder etc. rapid detection of semen is an important factor in confirming sexual assaults. Aim: To detect semen in the underwear of suspected women who were involved in sexual assault by using two rapid methods; the Ultra Violet Forensic Light Source (UV FLS), and detection of Prostate Specific Antigen (PSA). Material and methods: The study included 74 female cases of suspected sexual assault. The underwear of these cases were submitted to light screening by UV FLS, and then examined for the presence of prostate specific antigen as confirmatory test for the presence of semen.
Result; the majority of cases were under 30 years age. All cases were positive for UV light, (20.3%) of the underwear of these females showed positive results for PSA; the highest frequency was in the age group (21-30) years.
Conclusions: though the PSA test is highly sensitive and specific for semen detection, yet they are not conclusive as to the source of semen, and therefore, further test for DNA print is very necessary to determine the source of semen on the underwear of suspected women