Omar Mateen

Photo of a man said to be Omar Mateen, the man who killed at least 20 people inside an Orlando gay bar early Sunday morning

The man who opened fire inside a crowded gay bar in Orlando shortly before 2 a.m. has been identified as Omar Mateen, 29, of Fort Pierce, Fla.

Authorities have said they don’t know the motivation behind the shooting, but they are referring to it as an act of terrorism, because of the number of casualties, and early on suggested the shooter might have been “radicalized” through possible ties to Islamic jihadists.

Washington Post is reporting that Mateen’s family is from Afghanistan, but the shooter himself appears to have been born in the U.S. Relatives said Mateen’s family is in shock and is very sorry for what happened.