Once again I am reminded of this
They weren't cops, they're glorified bailiffs only allowed to go after specific individuals. This was just a murder. 
There are laws regarding what government employees can and can't have on their clothes. I'm referring to the criminal offense the shooter was technically committing. 
@VictimOfSimony @Tattooed_Mummy
It was an extra-judicial summary execution.
And they didn't even bother to make it a law officially.