In the early hours of Sunday, June 12, Omar Mateen opened fire at a gay nightclub in Orlando. The shooting and hostage situation at Pulse left 50 people dead, including Mateen, and more than 50 injured.
Officials are still investigating the exact motives for the shooting, but Mateen pledged allegiance to ISIS during the standoff with police. His family has also suggested he felt anger specifically toward gay people.
A picture of the gunman has begun to emerge. Mateen, 29, was a U.S. citizen and has Afghan parents. He was born in New York, according to the FBI. He was married, and had a young son.
He worked as a security guard, and had been investigated by the FBI before.
But there is much more to learn about the man accused of murdering dozens, and his motive behind it.
The investigation into the massacre at Pulse, and Mateen, could take months.
Here is the latest:
Thursday, June 16
- A former supervisor of Omar Mateen told CBS News that he would say he "could do nothing right in his father's eyes" and that his father would complain that Mateen didn't have any direction or know what to do in life.
- Between August 2000 and December 2002, Mateen was suspended from high school for a total of 48 days, according to disciplinary records obtained by CBS News from the two high schools he attended then. Most of the suspensions were for fighting or unspecified rule violations. Disciplinary records for Mateen aren't available after 2002, when he transferred to a third high school.
- President Obama and Vice President Joe Biden flew to Orlando to show solidarity with victims of the attack. The two wanted to convey that "Americans stand shoulder to shoulder" with the people of central Florida, White House spokesman Eric Schultz told reporters aboard Air Force One.
- With the help of a grand jury, investigators are stepping up their search for evidence that Mateen's wife, Noor Salman, may have played a role in the planning of the attack, CBS News homeland security correspondent Jeff Pegues reports. CBS News has learned that other family members are being looked at by investigators as well.
Wednesday, June 15
- A source familiar with the investigation told CBS News that Omar Mateen posted on Facebook moments before the attack: "You kill innocent women and children by doing us airstrikes..now taste the Islamic state vengeance" and "In the next few days you will see attacks from the Islamic State [ISIS] in the usa."
- At a press conference in Orlando, FBI agent Ron Hopper characterized the attack as a hate crime and terrorism. "This was an act of violence born out of hate that inflicted terror on an entire community," he said.
- Noor Salman, Mateen's wife, bought ammunition with her husband, CBS News homeland security correspondent Jeff Pegues reports.
- Footage from a 2012 award-winning documentary has emerged appearing to show Mateen working as a security guard contracted to the security company G4S following the 2010 BP oil spill. In the footage, he seemed skeptical of the cleanup efforts.
- During the three-hour attack, Mateen repeated his pledge to ISIS in a phone call to a television producer, according to a local cable news station. "Then he started saying he did it for the Islamic State, he did it for ISIS, and he started speaking in Arabic," said Matthew Gentili, a News 13 TV producer who received the call from Mateen.
Tuesday, June 14
- Omar Mateen went to work the day of the nightclub shooting as a guard in a gated community in Florida, CBS News has learned. He went home and then went on his shooting rampage at Pulse.
- During the attack, Mateen was pledging allegiance on his Facebook page to ISIS leader Abu Bakr al-Baghdadi and ISIS. He also called 911 to pledge allegiance.
- A law enforcement source says Mateen's wife Noor Salman is telling FBI investigators she tried to stop her husband from committing the attack, CBS News homeland security correspondent Jeff Pegues reports.
- Investigators now believe that Mateen was in the general area of the Pulse nightclub for several hours before entering the club at about 2 a.m. and launching the attack, Pegues reports.
- Authorities are trying to piece together all of Mateen's movements in the days and weeks before the mass shooting. They believe Mateen had also cased Disney World, once in April, with his wife, and then earlier in June, Pegues reports. Visits to Disney were likely captured by a vast security network at the resort.
- Club patron Jim Van Horn says Mateen was a regular at Pulse, which led to speculation about Mateen's sexual orientation. But Mateen's father on Tuesday, in his second interview with CBS News, said he did not believe that his son was gay.
- After reviewing evidence from Mateen's cellphone and computer, investigators concluded Mateen had been inspired by radical Islamist ideology.
- In 2013, while Mateen was an armed security guard at the St. Lucie County Courthouse, he was investigated by the FBI. Co-workers said he had boasted of family connections to al Qaeda and that he was a member of Hezbollah. Then, his name popped up in connection with an investigation into an American suicide bomber in Syria. In both cases he was cleared.
- FBI agents follow detailed guidelines in domestic investigations. In Mateen's case, they opened what is known as a preliminary investigation, which is limited to six months but can be extended. Mateen's case stretched over 10 months and included surveillance, informants as well as wiretaps. It ended in March 2014, when agents decided there wasn't enough evidence to determine that he was a terrorist.