The Las Vegas mass shooter set up cameras around the hotel room used in his deadly attack, police have said.

Clark County Sheriff Joseph Lombardo told reporters that the shooter installed the cameras both inside and outside his room at Mandalay Bay Resort and Casino, before opening fire on a country music concert below. At least one camera was installed on the service cart in the hallway.

The shooter may have installed cameras to watch for anyone approaching, Mr Lombardo said. All digital and electronic evidence has been taken into custody.

The shooter, identified by police as Stephen Paddock, was able to fire on the crowd for nine minutes before a SWAT team blasted through his door, Mr Lombardo said. The 64-year-old killed himself before officers could reach him.

Paddock's attack injured more than 500 people, and killed at least 59, making it the deadliest mass shooting in US history.

Authorities later found 23 weapons in Paddock's hotel room; 19 in his home in Mesquite, Nevada, and seven in his home in Reno. Explosive substances were also discovered in his home and car.

Las Vegas shooting – in pictures Show all 15 1 /15 Las Vegas shooting – in pictures Las Vegas shooting – in pictures People scramble for shelter at the Route 91 Harvest country music festival after gun fire was heard Getty Las Vegas shooting – in pictures People carry a person at the Route 91 Harvest country music festival after shots were fired David Becker/Getty Las Vegas shooting – in pictures People run from the Route 91 Harvest country music festival after gun fire was heard David Becker/Getty Las Vegas shooting – in pictures A handout photo released via Twitter by Eiki Hrafnsson (@EirikurH) showing concertgoers running away from the scene (C) after shots range out at the Route 91 Harvest festival on Las Vegas Boulevard EPA/Eiki Hrafnsson Las Vegas shooting – in pictures People lie on the ground at the Route 91 Harvest country music festival after hearing gun fire Getty Las Vegas shooting – in pictures A man in a wheelchair is taken away from the Route 91 Harvest country music festival after hearing gun fire David Becker/Getty Las Vegas shooting – in pictures People stand on the street outside the Mandalay Bay hotel near the scene of the Route 91 Harvest festival on Las Vegas Boulevard EPA/Paul Buck Las Vegas shooting – in pictures FBI agents confer in front of the Tropicana hotel-casino after a mass shooting during a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Las Vegas police run by a banner on the fence at the Route 91 Harvest country music festival grounds after shots were fired David Becker/Getty Las Vegas shooting – in pictures An injured person is tended to in the intersection of Tropicana Ave. and Las Vegas Boulevard after a mass shooting at a country music festival Ethan Miller/Getty Las Vegas shooting – in pictures Metro Police officers pass by the front of the Tropicana hotel-casino after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip AP/John Locher Las Vegas shooting – in pictures A cowboy hat lays in the street after shots were fired near a country music festival in Las Vegas Getty Las Vegas shooting – in pictures Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Sheriff Joe Lombardo (2-R) speaking during a press briefing in the aftermath of the active shooter incident on Las Vegas Boulevard EPA

The amount and type of weaponry found in the hotel room suggest the attack was "pre-planned extensively," Mr Lombardo said.

"The world has changed. And, you know, who would have ever imagine this situation," the sheriff added. "I couldn't imagine it. And for this individual to take it upon himself to create this chaos and harm is unspeakable."

Police have yet to determine a motive in the shooting.

Las Vegas shooting: What we know so far

Investigators are still hoping to interview Paddock's girlfriend, Marilou Danley, who remains a person of interest in the attack. Ms Danley was in her home country of the Philippines on the day of the shooting.

Paddock wired $100,000 to an account in the Philippines prior to shooting, according to NBC News, but it is unclear whether the money was meant for Ms Danley's use.

Employees at the Starbucks near Paddock's Mesquite home said he used to berate his girlfriend in front of them.

“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'," a Starbucks supervisor told the Los Angeles Times.

Mr Lombardo said on Monday that police were “continuing the investigation,” into Ms Danley.