Often at the scene of a shooting, investigators have little evidence to work with. The shooter usually runs away with the gun, leaving behind little more than a couple of spent shell casings. Scratches and marks on a shell casing can tie it to a certain gun barrel, but the analysis is difficult, and investigators need both the gun and the casing to make the connection. If only someone could make a bullet talk. We can. Since 1996, we have been developing micromachining technologies that could produce robust raised characters on small stamping devices for the firing and shell ejector mechanisms of handguns and rifles. The raised characters - say, the firearm serial number - would then emboss each shell casing when the gun fires. Upon ejection, the shell casings would become the principle investigative leads in shooting incidents, directing police to a known, specific firearm.