Recently, a man named Rex Heuermann was arrested for the deaths of four young women found along a sandy stretch of Ocean Parkway, on Gilgo Beach, Long Island. The case had been unsolved for over sixteen years until Heuermann’s cell phone records were obtained by police, together with a description of the vehicle he had used. DNA expert Dan Krane explains how detectives were able to match a few pieces of pizza to an alleged serial killer.