It was a bad day for cops, San Francisco residents, and a good day for one very violent person(s).

According to KTVU News, an AR-15 assault rifle was stolen when a parked, locked, unmarked police car was broken into over the weekend as the officers were working in the area.

This rifle is issued to specially trained police officers. Were they specially trained how to not leave the rifle in plain sight or lock it in the trunk when they aren't in the car with it? Were the cops in plain clothes or did this thief know he was stealing from the police? What area was this in? All valid concerns and questions that are still unclear at this time. But what is clear is that no one should be wandering the streets with a murder weapon like this. A Google image search of the rifle is horrifying. Even the Hello Kitty version (because, why not?) of an AR-15 is still gnarly.

There are several ways to tip off police, in case anyone who reads online blogs like SFist also knows someone who steals assault rifles and knows the location of the rifle. Call police at (415)553-1373, or anonymously tip at (415)575-4444, or forget anonymity and text your tip to TIP411.

Update, March 5th: Relax, everybody! SFPD found their missing weapon.