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 the approach of police officers as he carried out his rampage, officials said Tuesday.

Officials still haven’t offered a motive for why Stephen Paddock, 64, of Mesquite, Nev., opened fire at a concert across the street from the Mandalay Bay Resort and Casino on Sunday night, killing 59 people and himself, 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, said Clark County Sheriff Joe Lombardo.

Federal officials say the Las Vegas shooter had devices attached to 12 weapons that allow semiautomatic rifles to mimic fully automatic gunfire.

Bureau of Alcohol, Tobacco and Firearms Special Agent in Charge Jill Schneider also told reporters Tuesday that Stephen Paddock had nearly 50 guns in three locations.

She said he had a combination of rifles, shotguns and pistols.

The gun attachment that mimics automatic gunfire is a little-known device called a “bump stock” that was not widely sold. The stocks have been around for less than a decade, and Schneider said officials determined they were legal.

One Mandalay Bay security guard, who had become separated from police, was shot in the leg through the door of Paddock’s room when he approached, Lombardo said. The guard escaped and police surrounded the room, eventually breaking inside, where they discovered that Paddock had killed himself.

A photograph obtained by the German newspaper Bild showed part of the interior of Paddock’s suite. What appears to be an AR-style rifle rests on the floor. It is fitted with a scope to aid long-distance shooting and a bipod for steadying the shooter’s aim.

Lombardo said Paddock’s girlfriend, Marilou Danley, was in the Philippines but that authorities were hoping to talk to her soon. A federal law enforcement official said investigators had discovered significant recent bank transfers to an account in the Philippines belonging to Danley.

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,” said Esperanza Mendoza, supervisor of the Starbucks.

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.’?”

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.

The mass shooting has launched another debate over access to guns in the United States, with much scrutiny falling on the gunman’s use of the 12 “bump stock” devices .

President Donald Trump told reporters Tuesday that “we’ll be talking about gun laws as time goes by,” not stating whether he would be for or against certain regulations under debate.

Republican leaders made clear Tuesday that Congress will take no action on gun legislation in the wake of the massacre. They refused to entertain Democratic demands to expand background checks for gun purchases and tighten restrictions on semi-automatic weapons, but also shelved their own House bill that would have loosened access to gun silencers. “I think it's premature to be discussing legislative solutions, if there are any,” Senate Majority Leader Mitch McConnell, R-Ky.

Paddock had at least 23 weapons in his hotel room, mostly rifles originally designed for military use that have become popular among civilians in recent decades.

Automatic weapons — which unleash multiple bullets with a single pull of the trigger — are more heavily regulated under U.S. law than semiautomatic guns, which fire one bullet per trigger pull. But they are not banned outright. Paddock had apparently bought his guns legally and passed background checks.

The attack brought a tearful rebuke by late-night TV host Jimmy Kimmel, who grew up in Las Vegas.

He showed photographs of Republican senators who have voted against tighter gun-control laws.

Republican leaders “sent their thoughts and their prayers today, which is good,” Kimmel said. “They should be praying. They should be praying for God to forgive them for letting the gun lobby run this country.”

Matt Pearce reported from Los Angeles, Cindy Carcamo from Las Vegas and Louis Sahagun from Mesquite, Nev. Los Angeles Times staff writers Richard Winton, Joseph Tanfani and Kate Mather and Associated Press contributed.

matt.pearce@latimes.com