California could become the first state in the nation to require semi-automatic handguns include microscopic equipment for pressing an identifying mark into every bullet fired. Through newly developed technology, the firing pin of a semi-automatic weapon can stamp the gun's make and model onto a bullet shell as it leaves the chamber. The technology could help police investigate homicides and trace gun trafficking. Thirty-three California police chiefs and two county sheriffs support a bill, sponsored by Assemblyman Paul Koretz, D-West Hollywood, that would require the markers. "It has the potential to solve some significant crimes in some pretty large numbers,"...