Tuesday's developments in the Orlando shooting

People visit a vigil for the victims of the shooting at the Pulse gay nightclub in Orlando, Florida, June 14, 2016.

People visit a vigil for the victims of the shooting at the Pulse gay nightclub in Orlando, Florida, June 14, 2016.

Jim Young/Reuters

Omar Mateen, the 29-year-old shooter at Pulse nightclub in Orlando on Sunday, was born in the Queens borough of New York City.

While the FBI investigation into his motives and background continues, this is what we know so far: