Close Fish Hunter.

It is to build confidence in the officer's reliance on non-lethal force. Before OC you could shoot someone, club them, fist fight, or yell at them ("verbal judo") if they didn't comply or meant to do you or others harm. With OC and TASER there are two more steps on the force continuum, between yelling and fighting, that helps keep officer and the bad guys they come into contact from getting hurt.