US Patent 8037632 Identification control of firearm

A firearm including a trigger-actuated firing mechanism, a safety device that selectively prevents and permits the firing mechanism to be actuated, and an authentication device that cooperates with the safety device and which recognizes a feature of an authorized shooter, wherein the safety device is nominally in a position that permits the firing mechanism to be actuated and is moved to a position that prevents the firing mechanism from being actuated only if the authentication device does not recognize a would-be shooter as an authorized shooter.