Forensic scientists say they may be able to use sperm’s “death rate” as evidence of when a rape took place. They found that the chemical in spermicidal condoms - often used by rapists, causes sperm cells to die at a steady rate. The team from the National University in La Jolla, California, says its findings could help corroborate the evidence of a victim of defendant. The research is reported by New Scientist magazine. Spermicidal condoms may be left behind at the scene of the crime, and the researchers from the National University wanted to look at whether the spermicide nonoxyl-9 might affect DNA which could be used to identify rapists. They found that it did not, but a surprise finding was that when sperm were incubated with nonoxyl-9, their numbers appeared to fall at a steady rate.
