true.DNA Evidence Led to Shirley Leach KillerFollowing the conviction today of Ian OâCallaghan for the murder of Bury grandmother Shirley Leach more than a decade ago, Forensic Science Service scientist Jonathan Whitaker said:"There have been huge advances in DNA technology by the Forensic Science Service over the last decade. We have continually worked with Greater Manchester Police to apply all of these cutting-edge advances in an effort to solve this case, and ultimately it was DNA profiling that led police to O'Callaghan. This is an exceptional case which illustrates the power of DNA profiling and the National DNA Database in helping resolve some of the oldest unsolved cases, as well as current ones." O'Callaghan was charged with the murder after being stopped on 18 February 2006 in Moston. He gave a positive breath test and was arrested on suspicion of driving whilst under the influence of excess alcohol. In line with normal procedure, O'Callaghan was required to provide a DNA mouth swab and fingerprints to police. When O'Callaghan's DNA was loaded onto the National DNA database it matched the DNA found at the murder scene twelve years earlier.