Researchers blow whistle on forensic science method

If forensic experts have access to a suspect's gun, they can compare the microscopic markings from discarded shell casings with those found at a crime scene. Finding and reporting a mismatch can help free the innocent, just as a match can incriminate the guilty. But new research reveals mismatches are more likely than matches to be reported as 'inconclusive' in cartridge-case comparisons.