The gun lobby is fiercely, and so far successfully, blocking what easily could be the greatest technological breakthrough to catching killers and deterring others. The simple method allows bullet manufacturers to stamp a numeric code on shell casings that would make it very easy to identify the gun that fired the shot. But the National Rifle Association is lobbying against states enacting laws to require such "microstamping." The gun lobby is likely to prevail, given... (GunPolicy.org)