'Sperm clock' could pinpoint time of a rape / New Scientist, 5 Mar 2005

http://www.newscientist.com/article.ns?id=dn7079
Anne Gosline
"The predictable death of sperm in condoms laced with spermicide could help police pinpoint the time of a rape, and possibly even corroborate the testimony of the victim or the defendant. An increasing number of rapists are using condoms, forensic medical examiners report."