Authorities are continuing their investigation into the horrific mass shooting at a gay nightclub in Orlando Sunday that left at least 49 victims plus the shooter dead and 53 more wounded.
Here’s what we know as of Tuesday evening:
The shooter (deceased):
Omar Seddique Mateen, 29, of Fort Pierce, Fla., about 120 miles southeast of Orlando, is the suspected shooter.
Mateen was a U.S. citizen, born in New York.
He had been employed by the global security firm G4S since September 2007.
Mateen had both a security guard license and a statewide firearms license from the Florida Department of Agriculture and Consumer Services, however both licenses were listed as “decease/dissolved” on Monday.
Mateen was killed by police after a three-hour standoff at the Pulse nightclub.
Nothing in U.S. and Florida law would have prevented Manteen from legally buying the weapons authorities said he purchased days before the shooting, legal experts said.
Ongoing terror investigation:
Investigators believe Mateen was in the Orlando area several days before Sunday’s mass shooting familiarizing himself with the city, a federal law enforcement official told USA TODAY on Monday, suggesting that the gunman carefully considered his target.
Investigators are reviewing Mateen’s possible consideration of other iconic targets in the Orlando area, including Disney World. That review was ongoing and it was not immediately clear how seriously other locations were considered.
Before his death, Mateen talked to 911 dispatchers three times and swore his allegiance to the Islamic State.
FBI Director James Comey said that Mateen made contradictory statements about his affiliations during his conversations with 911 dispatchers and that he made reference to other terror groups that are enemies of ISIL.
Mateen praised the Tsarnaev brothers, who were responsible for the Boston Marathon bombing.
President Barack Obama and Comey said that there was no evidence that Mateen had direct contact with Islamic State militants but rather was inspired by extremist information available on the Internet.
President Obama said that the case is being treated as a terror investigation.
The FBI investigated and interviewed Mateen in 2013 for “inflammatory comments” he allegedly made to coworkers in which he expressed support for al Qaeda and a desire to martyr himself.
In 2014, the FBI investigated and interviewed Mateen again because of his connection to an American who carried out a suicide bombing in Syria.
In both cases the FBI did not find enough evidence to charge Mateen with a crime.
In a radio broadcast Monday, the extremist group said Mateen was “one of the soldiers of the caliphate in America,” thought it remains unclear if ISIL has any prior knowledge of the attack or any role in planning it.
The shootings started around 2 a.m. ET on Sunday, when an extra-duty police officer in full uniform providing security at Pulse Nightclub engaged Mateen in a gun battle.
Additional officers entered the club and forced the gunman to retreat into a bathroom where he took hostages.
Orlando Police Chief John Mina said that Mateen seemed “cool and calm” when police negotiators spoke with him.
Mina said that no shots were fired during negotiations but that the suspect made comments about bombs.
Police breached a wall with explosives and an armored vehicle when they believed further loss of life was imminent based on the phone conversations with Mateen.
Hostages were able to escape through a small hole in the wall that police created.
Police killed Mateen while he tried to crawl through the hole in the wall.
At least 49 people were killed and 53 were injured.
Original reports indicated that 50 had been killed, but that count included Mateen’s death too.
29 people are still in the hospital, and five of them are still in critical condition.
48 of the 49 victims have been identified, and the names of 48 victims have been released by the city of Orlando after their next of kin have been contacted.
The victims’ ages range from 18 to 50.
One police officer was also injured, but his Kevlar helmet protected him.
This handout photo provided by the Orlando Police Department
This handout photo provided by the Orlando Police Department on June 12, 2016, shows a bullet hole left in a kevlar helmet worn by an Orlando police officer that saved his life during the shootings at the Pulse nightclub in Orlando, Fla. (Photo: Orlando Police Department, via AFP/Getty Images)
2016 presidential candidates’ responses:
Hillary Clinton called for more bipartisanship in the effort to track potential terrorists online and for closing a loophole allowing individuals on a federal terrorism watch list from purchasing assault weapons.
Donald Trump said that assault rifles are needed for protection and reiterated his call for a temporary ban on Muslims entering the United States.
Ways to help:
OneBlood, a non-profit blood bank, announced an urgent need of blood donations in Orlando.
LGBT and humanitarian advocacy groups have also begun raising monetary donations for the shooting victims and their families.
Many vigils across the USA have already taken place to mourn the dead with many more to take place in the coming days.
The airline JetBlue is offering free flights to and from Orlando for family members and partners of those injured or killed in the shooting.
The shooter’s ex-wife and father:
Sitora Yusufiy said she was with Mateen just four months before she fled their home and filed for divorce.
Yusufiy said he was “bipolar” and alleges that he was physically abusive.
Yusufiy called Mateen “mentally unstable and mentally ill” as well as “obviously disturbed, deeply, and traumatized.”
Mateen’s father said that his son was angered when seeing two men kissing in Miami a few months ago.