MANY POLICE OFFICERS ARE KILLED BY THEIR FELLOW OFFICERS WHO MISTAKE THEM FOR ARMED FELONS. POLICE UNIONS HAVE BROUGHT SUIT AGAINST DEPARTMENTS AND COMMUNITIES TO RESCIND THE REQUIREMENT THAT POLICE OFFICERS BE ARMED 24 HOURS. THE REASON IS THAT THERE HAVE BEEN SO MANY SHOOTINGS THAT INVOLVED MISTAKEN IDENTITY. ELIMINATING THE OFF-DUTY GUN IS NOT ALWAYS THE ANSWER, AND THE THRUST HAS BEEN TO MAKE THE OFF-DUTY GUN OPTIONAL RATHER THAN TO ELIMINATE IT. FOUR STEPS THAT OFFICERS SHOULD TAKE WHEN THEY CHOOSE TO DRAW THEIR OFF-DUTY GUN IN CONFRONTATIONS WITH CRIMINALS ARE THE FOLLOWING: (1) BE SURE IT IS NECESSARY TO DRAW THE GUN, (2) CARRY A BADGE OF IDENTIFICATION, (3) MAKE SURE INCOMING OFFICERS KNOW WHO THE OFF-DUTY OFFICER IS, AND (4) DO NOT BE DISTRACTED. OFFICERS WHO USE THEIR OFF-DUTY GUN TO MAKE AN ARREST OR TO INTERVENE IN A VIOLENT CRIME MUST RECOGNIZE THAT THERE IS A DANGER OF BEING MISTAKEN FOR A FELON. THIS DANGER CAN BE ALLEVIATED BY AVOIDING OFF-DUTY CONFRONTATIONS WHEN A CLEAR AND PRESENT DANGER TO HUMAN LIFE DOES NOT EXIST. WHEN OFFICERS DO DECIDE TO USE THEIR POLICE POWERS WHILE OFF DUTY, THEY CAN OFTEN PREVENT CASES OF MISTAKEN IDENTITY BY CLEARLY IDENTIFYING THEMSELVES AS OFFICERS FROM THE FIRST MOMENT OF A CONFRONTATION. AN EFFORT SHOULD BE MADE TO CONTROL COMMUNICATIONS THAT GO ON TO POLICE HEADQUARTERS FROM THE SITE OF AN ARREST TO ASSURE THAT PATROLMEN COMING TO THE SITE WILL RECOGNIZE OFF-DUTY OFFICERS. PHOTOGRAPHS ARE INCLUDED. (DEP)