The former wife and acquaintances of the gunman who massacred 49 people at a gay club in Florida have suggested he may have been questioning his sexual orientation.
Omar Mateen pledged allegiance to Isis during the shooting in Orlando in the early hours of Sunday morning and authorities are treating the atrocity as a terror attack inspired by the group.
His father claimed he had become angry after recently seeing two men kiss but others said Mateen visited gay clubs and used same-sex dating apps.
Sitora Yusufiy, his ex-wife, reportedly told her fiancé the shooter had "gay tendencies".
In an interview with SBT Brazil television, Marcio Dias said she recalled Mateen's father accusing him of being homosexual several times in front of her before they divorced in 2011.
A man who was Mateen's class at the Indian River Community College police academy in 2006 said he showed romantic interest.
The man, who did not want to be named, told the Palm Beach Post: "We went to a few gay bars with him, and I was not out at the time, so I declined his offer."
He believed Mateen was gay but was not open about his preference, describing him as "socially awkward". Mateen did not become a police officer and was working as a G4S security guard at the time of his attack.
Another man said Mateen had messaged him for a year on the gay chat and dating app Jack'd but that they never met up.
Kevin West told the Los Angeles Times he was dropping off a friend at Pulse at 1am on Sunday morning when he recognised him crossing the road.
"He walked directly past me. I said, 'Hey,' and he turned and said, 'Hey,'" and nodded his head, West said. "I could tell by the eyes."
"Sometimes he would go over in the corner and sit and drink by himself, and other times he would get so drunk he was loud and belligerent," Ty Smith said.
Another frequent patron at Pulse, Jim Van Horn, described Mateen as a "regular".
"He was trying to pick up people. Men," he told the Associated Press, saying the man had once told him about his ex-wife.
The FBI said it was investigating whether Mateen had visited venues to scout them out for a possible attack.
"We are working to understand what role anti-gay bigotry may have played in motivating this attack," director James Comey said.
"But we are highly confident that this killer was radicalised and at least in some part through the internet."
He said Mateen had made supporting multiple armed Islamist movements and people, which "adds a little bit to the confusion about his motives".
Isis claimed responsibility for the shooting, calling Mateen "a soldier of the Caliphate", but there was no indication that the terrorist group had contact with the gunman or directed the atrocity.
"It does appear that at the last minute he announced allegiance to Isil (Isis) but there is no evidence so far that he was in fact directed by Isil or that it was part of a larger plot," Barack Obama said.
The 29-year-old was shot dead in a gun battle with police who stormed Pulse with armoured vehicles after a three-hour siege.
Mateen called 911 as he held hostages in a bathroom, pledging allegiance to Isis leader Abu Bakr al-Baghdadi and talking about the Boston bombers and a man who became a suicide bomber for the al-Qaeda-linked Jabhat al-Nusra in Syria.
Co-workers reported him to the FBI in 2013 after he had made "inflammatory and contradictory" statements, including a claim that he had family connections to al-Qaeda and Hezbollah but investigators found no evidence of a link.
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