The rampage, which ended when the gunman killed himself, is the latest mass shooting in recent years that appears to have targeted victims based on their race, religion or sexual orientation.
Prosecutors said the gunman made the attack in the name of Islamic State, although his motivations for choosing Pulse remain unclear.
Before the shooting, the gunman, who was shot and wounded by police, described his antisemitic feelings on social media.
He awaits trial on four other murder counts in Atlanta where he faces the death penalty if convicted.
Georgia prosecutors have said they intend to designate the case as a hate crime based on race or gender.
Persons:
EMANUEL CHURCH, Rich McKay, Rosalba O'Brien
Organizations:
Prosecutors, Islamic, Nazi, Mother, AME Church, Thomson
Locations:
Jacksonville , Florida, U.S, ORLANDO, Orlando , Florida, United States, New Orleans, Islamic State, PITTSBURGH, BUFFALO, New York, Buffalo, CHARLESTON, Charleston , South Carolina, ATLANTA, Atlanta, Georgia