The gunman who authorities said killed at least 58 people at a Las Vegas music festival appears to have used at least one fully automatic rifle and had more than a dozen other firearms in his hotel room, a law-enforcement official said.

Investigators found 18 to 20 firearms, some fully automatic, in a room on the 32nd floor of the Mandalay Bay Resort and Casino, the law-enforcement official said. That is from where the suspect, identified as 64-year-old Stephen Paddock, allegedly fired upon thousands of concertgoers below. The weapons included AR-15-style and AK-47-style rifles as well as a large cache of ammunition, the official said.