Yorkshire scientists have developed a new method to help detectives catch rapists who use condoms in an attempt to evade capture.
Police have seen a rise in cases in which sex offenders use protection, in a bid to avoid sexually transmitted diseases and to make sure they don't leave DNA evidence behind.
But a technique developed by academics at Sheffield Hallam University will enable forensic specialists to detect condom lubricant on fingermarks left at crime scenes.
The research team hopes the technique will eventually mean that lubricant found on fingermarks can be matched with samples taken from victims.
Dr Simona Francese, from the university's Biomedical Research Centre, said: "If condom lubricant can be detected in fingermarks it would improve the evidence for the prosecution by establishing the assailant's presence at the scene and, crucially, having had contact with a condom."
The BMRC research is published in the journal Rapid Communications in Mass Spectrometry.