The suspected gunman behind a mass shooting at an Orlando nightclub has been identified as Port St. Lucie resident Omar Mateen, CBS News confirms.
Officials are still investigating the exact motives for the shooting, and both ties to radical Islam as well as a general hate crime motivation are being considered.
Sources have confirmed to CBS News that authorities are investigating whether the suspect had ties to Islamic terrorism. Sources tell CBS News correspondent Jeff Pegeus that Mateen called 911 and pledged allegiance to ISIS. During the 911 call, Mateen referenced Boston marathon bombers Dzhokhar and Tamerlan Tsarnaev, Pegues reports.
Police have said the attack appears to be an act of domestic terrorism, and officials are investigating whether the attack may have been inspired or directed by a terrorism group like ISIS or Al Qaeda, Pegues reports.
Although some Twitter accounts linked to the terror group ISIS have described Mateen as a hero, the group has not officially claimed responsibility for the attack.
Law enforcement sources tell Pegues that Mateen was on their radar "in the last five years." There was no formal investigation opened and the suspect wasn't under investigation at the time of the mass shooting, Pegues reports. Sources also confirm to CBS News that Mateen worked as a security guard.
A U.S. intelligence source told Milton that Islamic terrorism is being investigated as a possible motive in the shooting because of several indicators, including the style of the attack, which had similarities to the attacks in Paris in November 2015 and Brussels in March. The gunman put up a protracted gun battle with police and was heavily armed, the source said.
Sources tell Milton that authorities investigating the incident are still looking into whether the attack is a hate crime.
The suspect had been married to Sitora Yusufiy for several months before divorcing in 2011, reports CBS news senior investigative producer Pat Milton. A former father-in-law says Mateen was abusive towards a former wife, Pegues reports.
A New Jersey man who identified himself as Yusufiy's father told CBS News his daughter was married to Mateen seven years ago. He said the two met online and had only known each other for a few months when she moved to Florida and married him.
"When we even heard that, we actually didn't like that," said the man, who didn't give his name. "Because we are people who believe in conservative traditions, and we said you know it's weird that you know this person for two to three months online."
The man said Mateen became abusive towards his daughter. The family went to Florida in September 2009 to pick up their daughter and called police to get her belongings, he said. She later filed for divorce.
Since then, the woman and her family have had no contact with Mateen, he said.
The family is from Uzbekistan and came to the U.S. in 2009, the man said. He said he was surprised to learn Mateen was the suspected gunman.
"I was really shocked, why would he do such a thing? So many people," the man said.
Officials are trying to piece together a profile of who the suspect was and hone in on his online footprint. A law enforcement source tells Milton investigators are seeking court authorized search warrants for the suspect's home, car, and communication devices including his cell phone and computer. Police have said the suspect was driving a van that was found outside the nightclub.
They are also seeking Mateen's financial records and phone records to determine who he may have been in contact with, including anyone overseas.
Authorities are investigating whether Mateen was on a terrorism watchlist, which could shed light on a possible motive, Pegues reports. Mateen has no apparent criminal history, according to sources.
Orlando Police Chief John Mina said the suspect was found with a handgun and an AR-15-style assault rifle. Grayson said all the victims were killed with a single assault-style rifle and that the slaying happened "very quickly." There's no current indication that Mateen had accomplices, police say.
The shooting and hostage situation early Sunday morning at Pulse -- which describes itself as "Orlando's hottest gay bar" -- left at least 50 people dead, including the gunman, and more than 50 injured, officials say.
Florida Rep. Alan Grayson said Mateen was an American citizen, though he said he has several family members who aren't. CBS News has confirmed that Mateen was born in the U.S., is 29 and has Afghan parents.
"I think it's more likely than not it was an ideologically motivated attack," Grayson said.
The suspect's father has spoken out to the media, saying his son was anti-gay and he doesn't believe the attack was motivated by religion.
The FBI says they haven't determined whether the massacre was a hate crime, but Grayson said he believes "it's no coincidence that the attack took place where it did and when it did."
"It might be that we've seen the commission of an awful hate crime last night," Grayson said.
Orlando Police Chief John Mina said an officer in full uniform was working extra duty at the club around 2 a.m. Sunday and heard reports of shots fired. He engaged the shooter, who went back inside the club and took hostages, Mina said. Clubgoers reported hearing multiple gunshots and fled amid a chaotic scene.
CBS News correspondent Jeff Pegues reports the suspect walked into the club heavily armed. He had an AR-15-style assault rifle and a handgun.
There was some concern initially that the gunman may have had a suspicious device, but investigators now believe that was not the case.
About three hours later, Mina said a decision was made to rescue the hostages, and officials say the suspect exchanged gunfire with a SWAT team. Law enforcement used flash-bang grenades and a SWAT vehicle to storm the building and may have saved the lives of nearly 30 being held hostage, CBS News reports. The suspected gunman was shot dead.
The attack is now the worst mass shooting in U.S. history.