The gist:
Something like 200 people had a snowball fight at 14th and U Streets in DC:
The snowballers were courteous: they ceased fire when cars went through, and even helped unstick a few cars that got stuck in the snow/slush.
Along comes this dude:

His Hummer got hit by a snowball, so he pulled a gun. So the snowballers called the cops.
Turned out he was a cop, only he wasn't wearing a uniform, driving a marked car, showing a badge, or verbally identifying himself as law enforcement.
The local news didn't seem to think that he had pulled his gun, but he admits it here:
P1: "what's your badge number sir?"
P1: "what's your badge number?"
C1: "for what?"
P1: "so we can report your ass for.."
P2: "cause you pulled a gun!"
P1: "pulling a gun at a.."
C1: "detective baylor, ok?"
P1: "detective baylor, ok."
P1: "for pulling a gun at a snowball fight"
C1: "yes I did, cause I got hit with snowballs!"
Gun vs. snowballs. Sure, that sounds rational.