Police are working to establish the motive behind a mass shooting which left at least 59 dead and another 527 injured at a Las Vegas concert.
Gunman Stephen Paddock, 64, opened fire from the 32nd floor of the Mandalay Bay Hotel towards an open-air music festival on Sunday evening.
Police found 23 guns in his hotel room, as well as “in excess of” 19 firearms and explosives at his Nevada home.
But as yet, no clear reason for the killing has emerged.
Investigators have found no link to international terrorism, despite a claim from so-called Islamic State. Some investigators have suggested psychological issues, but there is no confirmation of this.
The shooter was not known to police.
President Donald Trump described the attack as “pure evil” in an address from the White House on Monday.
What do we know of the gunman?
Stephen Paddock lived in a community of senior citizens in the small town of Mesquite, north-east of Las Vegas.
He reportedly lived with a woman called Marilou Danley who is out of the country in Japan, and does not appear to be involved, police said.
Las Vegas Sheriff Joseph Lombardo said when police searched the property after the attack they found 19 “additional firearms, some explosives and several thousand rounds of ammo, along with some electronic devices we’re evaluating at this point”.
Officers also found ammonium nitrate in Paddock’s car. The explosive found in his home was tannerite, the sheriff said.
There is a second house in northern Nevada which Swat teams are due to check for booby-traps before carrying out a search, Sheriff Lombardo said.
David Famiglietti of the New Frontier Armory told the BBC that Paddock had purchased firearms at his store in North Las Vegas in the spring of this year, meeting all state and federal requirements, including an FBI background check.
However, the shotgun and rifle Paddock bought would not have been “capable of what we’ve seen and heard in the video without modification,” Mr Famiglietti said.
Despite the large cache of weapons in his home, his brother, Eric, is dumbfounded that he acted this way.
Las Vegas Sheriff Joe Lombardo described the shooting as a “lone wolf” attack.
So-called Islamic State (IS) has claimed to be behind the attack, saying Paddock had converted to Islam some months ago.
But the group provided no evidence for this and has made unsubstantiated claims in the past.
FBI Special Agent Aaron Rouse told a news conference: “We have determined at this point no connection to an international terrorist organisation.”
IS’s claim of responsibility for the Las Vegas attack is very unusual in that the perpetrator’s profile does not fit that of supporters or “soldiers” that the group has claimed in the past, writes Mina al-Lami, who monitors jihadist groups for the BBC.
If true, his suicide would be deemed wholly “un-Islamic”, she adds.
Jihadist suicides involve the assailant blowing himself up in order to kill those around him.