That isn't the point of the exercise. Suppose you're an officer responding to a shootout between two randoms. The tape signals whether either of them are polic

That isn't the point of the exercise. Suppose you're an officer responding to a shootout between two randoms. The tape signals whether either of them are police. (This is why I would never carry a gun in this country. Suppose you do stop some sort of crime in public at gunpoint-- any trigger-happy idiot who walks in is going to see you as the aggressor.)