From CNN.com:

Orlando shooting suspect Omar Mateen was interviewed by the FBI in 2013 and 2014, FBI Assistant Special Agent Ronald Hopper told reporters Sunday. “Those interviews turned out to be inconclusive, so there was nothing to keep the investigation going,” Hopper said. Mateen was not under investigation at the time of Sunday’s shooting and was not under surveillance, Hopper said.
An American-born man who’d pledged allegiance to ISIS gunned down 50 people at a gay nightclub in Orlando — the deadliest mass shooting in the United States and the nation’s worst terror attack since 911, authorities said Sunday.
* The gunman was Omar Mateen of Fort Pierce, Florida, a law enforcement source told CNN.
* Mateen called 911 around the time of the attack to pledge allegiance to ISIS and mentioned the Boston bombers, according to a U.S. official.
* Orlando police shot and killed Mateen.
Mateen carried an assault rifle and a pistol into the packed Pulse club about 2 a.m. Friday and started shooting, killing 50 people and wounding at least 53, police said. After a standoff of about three hours, police crashed into the building with an armored vehicle and killed Mateen.
“It appears he was organized and well-prepared,” Orlando Police Chief John Mina said early Sunday. Authorities have not described finding any accomplices.
There has been no claim of responsibility for the attack on jihadi forums, but ISIS sympathizers have reacted by praising the attack on pro-Islamic State forums.
“We know enough to say this was an act of terror and act of hate,” President Obama said in an address to the nation from the White House. (more…)