title: Hospital wet mount examination for the presence of sperm in sexual assault cases is of questionable value.
abstract: Many protocols for the examination of sexual assault victims include the preparation of vaginal wet mount slides to determine whether sperm are present and if so, whether the sperm are motile. We have reviewed findings in 501 case reports to compare the efficiency of sperm detection on wet mounts to subsequent crime laboratory results of sperm searches on vaginal swabs. Sperm were detected on wet mounts in only 41% of cases in which sperm were detected in the crime laboratory. Motile sperm were observed in only 12% of cases reporting a 0-9 h postcoital interval; in three cases, motile sperm were seen at 15 h and beyond, indicating that motile sperm are not reliable evidence of a short postcoital interval. These findings demonstrate that wet mount examinations are of little value in guiding subsequent analyses in the crime laboratory or in corroborating other investigative aspects of the case.
authors.affiliation: Criminalistics Division, Oakland Police Department, 455 7th Street, Oakland, CA.
authors.forename: Shannon
authors.initials: S
authors.lastname: Cavness
authors.forename: Asha
authors.initials: A
authors.lastname: Choudhury
authors.forename: George
authors.initials: G
authors.lastname: Sensabaugh
mesh_terms: D016172:DNA Fingerprinting; D005260:Female; D005554:Forensic Medicine; D006801:Humans; D008297:Male; D008853:Microscopy; D011902:Rape; D013081:Sperm Motility; D013094:Spermatozoa / Q000166:cytology*; D013997:Time Factors; D014621:Vagina / Q000166:cytology*; D014626:Vaginal Smears
keywords: clinical forensic medicine; forensic biology; forensic science; motile sperm; rape victim examination; sexual assault; sexual assault evidence; sperm detection; wet mount