By Mike Heuer, Courthouse News

LAS VEGAS (CN) – The gunman who rained bullets on concertgoers in Las Vegas on Sunday evening – killing at least 59 and wounding some 527 others – had been stockpiling weapons and a fertilizer often linked to homemade bombs was found in his car, according to law enforcement officials.

Clark County Sheriff Joe Lombardo said during a news conference Monday that Steven Paddock, 64, had at least 16 rifles, about 500 rounds of ammunition, scopes and two tripods with him during a weekend stay at the Mandalay Bay casino. He said police believed some of the military-style rifles had been illegally converted into fully automatic weapons, something he said federal Alcohol, Tobacco and Firearms agents will determine.

Lombardo also said police had found ammonium nitrate – the same fertilizer used to make the bomb that leveled a third of the federal building in Oklahoma City in 1995 – in Paddock’s car, and many more guns at his home in a retirement community in Mesquite, Nevada.

Paddock used a device similar to a hammer to break out two hotel windows in adjoining rooms on the 32nd floor of the Mandalay Bay casino, Lombardo said. Paddock then opened fire on an outdoor concert venue located on the east side the Las Vegas Strip and across from the casino, just as country star Jason Aldean had begun the final set of the 3-day festival.

Paddock himself just before a SWAT team entered his hotel room, police said.

Dead bodies remained at the scene until Monday evening, and local hospitals are in dire need of blood donations.

Local hospital officials said more blood will be needed for several days, and asked would-be donors to schedule appointments to reduce the hours-long wait at area blood donation centers.

News reports indicate Paddock, 64, is a retired accountant and auditor who moved to Mesquite a year ago from Reno.

He reportedly gambled heavily since his retirement, spending tens of thousands of dollars in recent weeks.

Mesquite Police said they had no problems with Paddock during his one-year stay there and were searching his home for additional evidence and information.

Paddock had no criminal record. But his father, Benjamin Paddock, was a former bank robber and was on the FBI’s 10 most wanted list in 1968.

The shooting occurred after 10 p.m. during the closing set of the three-day Route 91 country music festival.

The Islamic State of Iraq and Syria claimed Paddock had converted to Islam several months before and carried out the attack on its behalf, but the FBI quickly denied any connection between Paddock and ISIS.