It was an AK, but no word on whether it was actually an automatic or not... they're commonly converted to semi auto (like M16s/AR15s), and when so modified are actually legal and considered an unrestricted firearm (provided magazine capacity is under a certain size). Still some scary shit though. The house that was targeted is actually directly behind my coworker's.
That being said, I can't help but laugh at the morons that hit the wrong house... I immediately thought of the scene from "Snatch" where the guys are preparing to hold up the Bookie and one of them shows off the gun they're going to use for it:
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