BRITAIN’S most senior murder investigator has called for DNA to be taken from babies. Commander Dave Johnston said it would build up a database to solve crimes and prevent others. He said samples could also be taken from Britons renewing passports and from migrants arriving here. The head of the Met Police’s Homicide and Serious Crime Unit, went on: “We have 300,000 unsolved cases where we have taken a profile at a crime scene but have not yet matched it. “As well as solving crime, it would really make someone think twice about committing crime if they knew their DNA...