Police believe that the 19-year-old who opened fire in a Nebraska shopping mall yesterday had stolen the assault rifle he used from his stepfather's home.
They say the weapon was an AK-47.
He's believed to have smuggled the rifle into the mall under some clothing he was carrying.
The mall remains closed today, as authorities continue to investigate the shooting and what may have prompted it.
Robert Hawkins took his own life after killing six store employees and two customers.