when the looting starts, the shooting starts

Etymology
Originally used by, the police chief of Miami, Florida, in response to an outbreak of violent crime during the 1967 Christmas holiday season. He accused "young hoodlums, from 15 to 21", of "taking advantage of the civil rights campaign" that was then sweeping the United States.

Proverb

 * 1)  Lethal force is justified against rioters and looters.

Usage notes

 * Especially used in the context of civil rights protests in the United States.