LAS VEGAS — The gunman who attacked a Las Vegas country music festival installed cameras outside his hotel room, including at least one in a room service cart, to watch for approaching police officers as he carried out his rampage, officials said Tuesday.

Officials still haven't offered a motive for why Stephen Paddock, 64, Mesquite, Nev., a gambling aficionado and real estate investor, opened fire at a concert across the street from the Mandalay Bay Resort & Casino on Sunday night, killing 59 and injuring more than 500.

But additional information obtained by investigators revealed the extent to which Paddock, who owned dozens of guns, apparently "preplanned extensively" for the attack, Clark County Sheriff Joe Lombardo said.

Before the attack, Paddock placed two cameras outside his suite and one inside, on the peephole of his door, to watch for approaching police, authorities said.

New details emerged Tuesday about Paddock, who according to federal records held a series of federal jobs through the years. He was a former U.S. Postal Service letter carrier in the 1970s, and after graduating from California State University-Northridge with a degree in business administration in 1977, he became an agent for the Internal Revenue Service, a job he held from 1978 to 1984. He then was employed as an auditor for the Defense Contract Audit Agency for a little more than a year, federal personnel records showed.

Inspection of the weapons found at the scene of the shooting showed at least 14 of the firearms had been legally modified with "bump stock" accessories that allow a shooter to fire rounds at a rapid pace, according to Jill A. Snyder, the Special Agent in Charge of the San Francisco division of the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Paddock owned at least 47 guns purchased in Nevada, Utah, California and Texas, and he brought at least 23 weapons to his hotel room, mostly rifles, officials said.

Lombardo said authorities are hoping to talk soon with Paddock's girlfriend, Marilou Danley, who was traveling in the Philippines.

A federal law enforcement official said investigators had discovered significant recent bank transfers to an account in the Philippines belonging to Danley. The Clark County Sheriff's Department said the FBI had filed a subpoena for financial records to trace Paddock's money.

Paddock had a history of berating his girlfriend publicly, according to baristas at the Starbucks inside the Virgin River Casino in Mesquite, where the couple were frequent customers.

"It happened a lot," Esperanza Mendoza, supervisor of the Starbucks, said Tuesday.

Paddock's abuse would come when Danley asked to use his casino card to make the purchase, Mendoza said. The card enables gamblers to use credits earned on electronic gambling machines to pay for souvenirs or food at the casino.

"He would glare down at her and say — with a mean attitude — 'You don't need my casino card for this. I'm paying for your drink, just like I'm paying for you.' Then she would softly say, 'OK' and step back behind him. He was so rude to her in front of us."

In addition to raiding the couple's home in Mesquite, police also raided their home in a retirement community in the rolling foothills outside Reno. Investigators recovered five handguns, two shotguns and ammunition there.

Neighbor Susan Page, a retired financial analyst, rarely saw the couple. She said Paddock left the house for good sometime near the middle of August. She last saw Danley a week later, she said. Danley was packing up her car, piling things on the roof.