What does it matter? The powers that be want Americans disarmed before the SHTF. This event will be played politically to provide the leverage they need to go much further in that pursuit.
Congress readies new gun-control bills after Gabrielle Giffords shooting
..limiting the number of rounds in a clip, and banning guns within 1,000 feet government officials is (IMO) just the starting point of the proposed new gun control bills. It will be interesting to see how far they are permitted to go, and how much they end up getting away with.