The last words Michael Chad Breinholt heard were, “You’re about to die, my friend.”
[…]
With his hands cuffed behind his back, he briefly wrestled with two officers. One screamed that Breinholt was grabbing his holstered gun. Sgt. Tyler Longman rushed into the room, made his declaration and fired.
This argument states if an exception exists or has to be stated, then this exception proves that there must be some rule to which the case is an exception.
[…]
VIDEO: A Utah Police Officer Killed a Man Inside the Police Department. It Was His Third Shooting.
You’re not wrong, but:
https://en.wikipedia.org/wiki/Exception_that_proves_the_rule
One murder does not mean it happens regularly.