ORLANDO, Florida (REUTERS) - The wife of the gunman who killed 49 people at an Orlando gay nightclub over the weekend tried to talk him out of the attack, the deadliest mass shooting in modern US history, media reported on Tuesday, citing law enforcement sources.
Omar Mateen, who was shot dead by police after a three-hour standoff at the Pulse club early on Sunday, called 911 during his rampage to profess allegiance to various militant Islamist groups.
Federal investigators have said Mateen was likely self-radicalised and there was no evidence that he received any instruction or aid from outside groups such as Islamic State in Iraq and Syria (ISIS).
Mateen, 29, was a US citizen, born in New York of Afghan immigrant parents.
"He appears to have been an angry, disturbed, unstable young man who became radicalised," President Barack Obama told reporters after a meeting of the National Security Council.
MSNBC reported, citing multiple unnamed sources, that Mateen's current wife, identified by his family as Noor Mateen, told law enforcement officials that she drove him to multiple sites that he was considering attacking and was with him when he bought ammunition but she tried to talk him out of the attack.
Noor Mateen could not be reached for comment.
Omar Mateen's father, Seddique Mateen, told reporters outside his home on Tuesday that he had seen his three-and-a-half year old grandson today, but he declined to give information about Noor Mateen's whereabouts.
"We'll wait for the law enforcement," he said.
One official familiar with the investigation, who spoke on condition of anonymity, said investigators were only beginning to delve into the contents of Mateen's cellphone and other electronic devices. The source said investigators believe Mateen browsed militant Islamic material on the internet for two years or more before the Orlando shootings.
Soon after the attack, Mateen's father indicated that his son had harboured strong anti-gay feelings. He recounted an incident when his son became angry when he saw two men kissing in downtown Miami while out with his wife and son.
The Orlando killings came six months after the massacre of 14 people in San Bernardino, California, by a married couple professing Islamist militant ideologies.
Angel Colon, who was in Pulse with friends when Mateen attacked, described hearing gunfire and falling to the floor, shot in the left leg.
"I couldn't walk at all," Colon told a reporters at Orlando Regional Medical Centre, where he is one of 27 survivors being treated.
"All I could do was lay down. People were running over me."
Colon said he had a hopeful moment when Mateen went into a bathroom, where he later took hostages, but the gunman then emerged, systematically making his way through the club shooting people who were already down, apparently to ensure they were dead.
"I look over and he shoots the girl next to me and I was just there laying down and thinking, 'I'm next, I'm dead," Colon said.
Mateen shot him twice more, one bullet apparently aimed for Colon's head striking his hand, and another hitting his hip, Colon recalled.
"I was just prepared to stay there laying down so he wouldn't know I was alive," Colon said. When police drove Mateen back into a restroom, an officer dragged Colon to safety, he said.
US officials were investigating media reports that Mateen may have been gay but not openly so, and questioning whether that could have driven his attack, according to two people who have been briefed regularly on the investigation and requested anonymity to discuss it.
The owner of Pulse, speaking through a representative, denied reports that Mateen had been a regular patron of the nightclub.
"Untrue and totally ridiculous," Sara Brady, a spokeswoman for club owner Barbara Poma, said in an e-mail when asked about the claim.
Mateen's father told reporters on Tuesday that his son had never mentioned being homosexual. "I don't believe he was a whatever you call it," he said.
Obama noted that Mateen had used an assault rifle, and he called for a renewed federal ban on that kind of weapon.
Assault weapons were used in the San Bernardino shootings and in massacres in Aurora, Colorado and Newtown, Connecticut.
"Enough talking about being tough on terrorism," Obama said."Actually be tough on terrorism and stop making it easy as possible for terrorists to buy assault weapons."
Prior to Obama's comments, the National Rifle Association said in an op-ed published by USA Today on Tuesday, "Radical Islamic terrorists are not deterred by gun control laws." Chris Cox, executive director of the NRA's Institute for Legislative Action, wrote: "The San Bernardino terrorist attack wasn't stopped by California's so-called 'assault weapons' ban."
SUPPORT FOR MILITANT GROUPS
During his rampage, Mateen made calls to emergency 911 dispatchers in which he pledged loyalty to the leader of Islamic State, Abu Bakr al-Baghdadi, whose organisation controls parts of Iraq and Syria.
He also claimed solidarity in those calls with the ethnic Chechen brothers who carried out the deadly 2013 Boston Marathon bombing and with a Palestinian-American who became a suicide bomber in Syria for the al Qaeda offshoot known as the Nusra Front, authorities said.
ISIS and the Nusra Front are at odds in Syria's civil war, while al Qaeda and Hezbollah are also bitter enemies.
Mateen's name was listed on an unclassified federal database for nearly a year between 2013 and 2014 after he allegedly told co-workers of sympathies he had with militants overseas, three federal officials familiar with the investigation told Reuters.
He was removed from this so-called selectee list after the Federal Bureau of Investigation completed an investigation and concluded that he had no connections with known terrorist groups, two of the officials said. The FBI closed that investigation after about 10 months.
One added that investigators concluded that Mateen, who at times claimed ties to groups that are fighting one another, may have been a "fantasist."
ISIS reiterated on Monday a claim of responsibility, although it offered no signs to indicate coordination with the gunman.