A STRAY hair, or a spatter of blood or saliva, is all it takes to prove that a suspect was at the scene of a crime. But until now, there was no way of knowing when the suspect was there – an element of doubt often exploited by defence lawyers. An ingenious new technique that measures how quickly genetic material breaks down could change that.
DNA profiling is now a ubiquitous forensic tool. This month, the UK police force collected its millionth DNA sample. But DNA profiling cannot give an indication of the age of a biological sample, and though there…
