Officials say accused Las Vegas shooter Stephen Paddock had been stockpiling guns since 1982 and had bought 33 firearms in the last year.
Most of the firearms bought in the last year were rifles.
According to officials, Paddock bought the last gun on Sept. 28, just three days before the attack in Las Vegas.
An ATF official says they wouldn't get notified of a rifle purchase unless there were multiple guns bought at the same time.