ORLANDO -- FBI and law enforcement officials in Florida say a shooter who killed 50 people at gay night club Pulse had been investigated on two separate occasions in connection with terrorist sympathies.
Omar Mateen, according to police, called 911 before the shooting and expressed an allegiance to the Islamic State. Law enforcement confirmed the call happened during a news conference today.
U.S. Sen. Bill Nelson, a Florida Democrat, reported that the Islamic State News Service has claimed responsibility for the attack. In an appearance before the press with Florida's other senator, Marco Rubio, Nelson said the FBI is continuing to look the true motives of the attack.
"As you know it is difficult to stop a lone wolf attack because it is difficult to get information ahead of time," Nelson said. "In this case, we are getting information from the news agency for the Islamic State. We'll have to see."
Elected officials in Orlando expressed solidarity with the gay community. Rubio, a Republican, took the podium shortly afterward and stressed that America should unite as one community in the wake of the attack.
"Regardless of sexual orientation, regardless of political ideology, we are all Americans," he said. "The Islamic terrorists in the world will not win. We are all in this."
Orlando Mayor Buddy Dyer called today the saddest in his city's history, while Florida Gov. Rick Scott said there would always be swift justice for those intent on doing citizens harm.
Authorities also confirmed that 11 Orlando police officers and three Orange County sheriff's deputies engaged in gunfire with the suspect. All officers have been put on leave. Identities of the victims will be released as next of kin are notified. The next of kin of six victims have been notified so far.
Watch the FBI detail its interactions with Mateen:
