The photo from Omar Mateen’s high school yearbook is hardly remarkable — a toothy, dimpled smile with a peach-fuzz mustache below a mop of black hair.
His transformation from high school football player to perpetrator of America's worst mass shooting raises questions about whether red flags were missed over the depth of his apparent sympathies with Muslim extremists.
As families of the victims grieved and the nation recoiled at the scale of yet another mass shooting, a picture began to emerge of the 29-year-old killer as a quiet, devout person who in recent years displayed a hateful and violent streak.
Early on Sunday, he stormed a packed gay nightclub in Orlando, Florida, with a handgun and AR-15 semi-automatic rifle, fatally shooting 50 people before police killed him. Fifty-three others were wounded, many critically.
His ex-wife, Sitora Yusufiy, described him as "bipolar," and emotionally disturbed with a violent temper. She said she had been beaten and otherwise physically abused by Mateen during outbursts in which he would "express hatred towards everything". She was "rescued" by family members just four months into a stormy marriage that began in 2009 and ended in divorce, she said.
"He would often get into fights with his parents, but as I was the only one in his life most of the violence was directed towards me,” she told reporters in Boulder, Colorado outside a home where she was staying.
She said he aspired to be a police officer and had worked as a correctional officer at a detention center for juvenile delinquents in Fort Pierce, Florida, and had once sought admission to a police academy.
In Fort Pierce on Florida’s southeast coast, 120 miles (195 km) from the shooting, the imam at the mosque that Mateen attended for nearly 10 years described him as a regular worshipper who was quiet and rarely interacted with the congregation.
"He hardly had any friends," Syed Shafeeq Rahman, who heads the Islamic Center of Fort Pierce, told Reuters. "He would come with his little son at night to pray and after he would leave."
Rahman said Mateen never approached him regarding any concerns about homosexuals.
He usually prayed at the mosque a few times a week, mostly in evenings and as recently as Friday, but he didn't display signs of radicalism, according to fellow worshippers interviewed by Reuters.
Mateen was born in New York of Afghan descent but spent most of his life in Florida, attending Martin County High School in Stuart, a small city about a 20-minute drive from the Fort Pierce condominium where had most recently lived.
A classmate described him as a typical teen who played football. A school yearbook image of Mateen was seen by Reuters.
Samuel King, who was one year ahead of Mateen, said the two often spoke after Mateen graduated in 2004.
King waited tables at Ruby Tuesday’s restaurant at Treasure Coast Square, a mall where Mateen worked at GNC, the nutrition store, he said.
King said the Mateen he knew until 2009 did not appear to be anti-homosexual.
“What is shocking to me is that the majority of the staff at Ruby Tuesday’s when I worked there were gay. He clearly was not anti-(gay) at least not back then. He did not show any hatred to any of us."
While at GNC, Mateen lifted weights and "got really buff," King said, describing Mateen as gregarious and talkative in the immediate years after high school. “Something must have changed" since he last saw him, he added.
Mateen's father, Mir Seddique, told NBC News the massacre was not related to religion. He said his son turned angry when he saw two men kissing in Miami a couple of months ago.
The FBI twice interviewed Mateen for having suspected ties to Islamist militants. The first investigation took place in 2013 when Mateen made inflammatory comments to co-workers that indicated sympathy for militants, FBI special agent in charge Ron Hopper told a news conference in Orlando.
President Obama denounced the killing of 50 people in a Florida gay nightclub as an act of terror and hate, while Omar Mateen's ex-wife described the suspected gunman as "mentally ill." Law enforcement officials are examining evidence that Mateen was inspired by Islamic State militants.
The Afghan-born father of Omar Mateen, the man police identified as the gunman who killed 50 people at a packed gay nightclub in Florida on Sunday, is a fringe political commentator who rails against Pakistan and Afghan President Ashraf Ghani.
Seddique Mateen, who public records indicate is the father of Omar Mateen, had an occasional television show on a U.S.-based Afghan satellite channel for about three years, and has continued to post political commentaries on his Facebook page as recently as Sunday.
Omar Khatab, the owner of the California-based satellite channel Payam-e-Afghan, said in an interview that Seddique Mateen occasionally bought time on his channel to broadcast a show called "Durand Jirga," which focused in part on the disputed Durand Line, the frontier between Afghanistan and Pakistan demarcated by the Indian subcontinent's former British rulers.
In an interview with NBC News on Sunday, Seddique Mateen, also known as Mir Siddique, said his son's rampage had "nothing to do with religion."
He described an incident in downtown Miami in which his son, US-born Omar Mateen, 29, of Florida, saw two men kissing in front of his wife and child and became very angry.
"We are saying we are apologising for the whole incident," NBC News quoted Seddique Mateen as saying. "We weren't aware of any action he is taking. We are in shock like the whole country."
Seddique Mateen lives in Florida, according to public records, but it was not immediately known when he came to the United States. He did not return messages left on his phone, which appeared to be turned off, or respond to an email.
Khatab said Seddique Mateen would show up at his studio in Canoga Park, California, "three or four times a year" to tape his shows.
"He'd talk for about two to three hours," Khatab said in a phone interview. "He'd buy his own time and come here and broadcast and leave within a day."
Critical of Pakistan's ISI
Khatab said Seddique Mateen's political views were largely anti-Pakistan. A YouTube channel under Mateen's name had more than 100 videos posted between 2012 and 2015.
One of the videos refers to the "killer ISI" — the acronym for Pakistan's main military-run intelligence service — and says the agency is the "creator and father of the world's terrorism."
U.S. officials have accused Pakistani intelligence of backing violence against U.S. targets in Afghanistan, although Pakistan denies the allegations.
U.S. officials cautioned that they had no immediate evidence of any direct connection between the Florida attack and Islamic State or other foreign extremist group, nor had they uncovered any contacts between Omar Mateen and any such group.
Fifty-three people were wounded in the rampage. It was the deadliest single U.S. mass shooting incident, eclipsing the 2007 massacre of 32 people at Virginia Tech university.
Seddique Mateen interviewed Afghan President Ashraf Ghani in January 2014, according to a video posted on his YouTube channel.
The interview touched on economic development and youth unemployment in Afghanistan. Khatab said Mateen conducted the interview in Kabul and brought it to California for broadcast.
During the interview Mateen praised Ghani but by the following year had changed his views, apparently angered by Ghani's outreach to Pakistan in his bid to start peace talks with the Taliban.
In a 2015 video, Mateen declared his own candidacy for the Afghan presidency, even though there was no election at that time.
In the videos, he wears a Western suit and tie and speaks Dari, a dialect of Persian spoken in northern Afghanistan. He harshly criticizes Ghani's policies both at home and abroad and lashes out at Pakistan, its intelligence service, former Afghan President Hamid Karzai, and some senior Afghan government officials and jihadist figures.
In a February video on his Facebook page, he addresses Taliban members and castigates them for being the "servants" of the ISI.
In a June 11 video posted on Facebook, Mateen is dressed in military fatigues and says Afghanistan must "punish the traitors."
"I wish a hero one day removes Ashraf Ghani's turban and slaps this crazy man," he said in the video. "This traitor has rolled up his sleeves to destroy our country." On Twitter, Ghani condemned the Orlando attack and called it an "act of terror."