The Model 15 is a revolver created by the Smith & Wesson firearm industry. They were produced from 1949-1999. The Model 15 holds .38 Special and can fire up to 6 rounds. It only appears in Die Hard and was Al Powell's service pistol while with the LAPD.
Disguising himself as a hostage, Karl emerges from the sheet covering his Steyr AUG with him, and attempts to kill John McClane one last time. But before he can fire at him, Sergeant Powell of the LAPD draws his gun quickly, and shoots Karl multiple times with it, eventually killing him and saving McClane and his wife Holly Gennero.