The man rushed on to the stage at the Alrosa Villa just as the heavy metal band Damageplan was opening its show.
He shot and killed guitarist Dimebag Darrel Abbott, the club bouncer and
Two people were injured in the shooting.
Police Sergeant Brent Mull told CNN that the gunman, yet to be identified, was "targeting members in the band."
One of those wounded was in a critical condition, while the other sustained "non-life-threatening injuries," he said.
Two others were treated at the scene.