Phoenix Police Officer responds to a domestic, enters a home with the mother’s permission, son inside tells officer he needs a warrant. The officer responds by putting a gun to the victim’s head, saying “I don’t need no warrant, motherfucker.” Seconds later, the victims dog was shot and killed, then the victim himself.
Update: although this took place last year (timeline of events), it is still a compelling story. It appears as if no criminal charges were ever filed, although the mother of the murdered victim is pressing ahead with a civil suit, and the officer was eventually fired.
http://newsjunkiepost.com/2011/07/21/arizona-police-officer-executes-man-for-telling-him-a-warrant-is-needed/
http://www.youtube.com/watch?feature=player_embedded&v=Jv8ATRX4w-M