Because as common law appreciated, not only does an armed individual have the ability to protect himself or herself but criminals are less likely to attack them.

BBC: Man with shotgun

And finally, he is accused of lying about a variety of actions aimed at concealing his improper and embarrassing relationship with Ms. Lewinsky, when each one of those actions was motivated by nothing more than a desire to protect himself and his family from embarrassment, if not destruction.

CNN

Authorities have said Zimmerman was not immediately charged because there were no grounds, at the outset, to disprove his account that he had acted to protect himself.

CNN: STORY HIGHLIGHTS