It WILL be an AR-15. Period, end of story. This happened in CA a few years back at some nail salons and jerk joints. There were 12ga shotgun shells all over the floor in the news clip and they kept beating the AR-15 drum.....Just wait.
They will try like hell to hang it on an "evil military assault rifle in citizen's hands", failing this, it will be a SA pistol with "unregistered high capacity magazine clip."