In the wake of deadly school shootings and a new call for gun control legislation, new technology to link cartridge cases to guns by engraving microscopic codes on the firing pin has been found to be feasible. But it doesn't work well for all weapons and ammunition tested in a pilot study by researchers from the forensic science program at UC Davis. The study, released Thursday, determined that more testing in a wider range of firearms is needed to determine the... (GunPolicy.org)