Investigators say Johnson hit a curb and damaged his tire as he was leaving the club. He pulled over into the gas station to change the flat. While pulled over, police say Johnson was shot twice in the back. He died from his injuries.
"We have multiple, multiple witnesses from Bourbon Street where the disturbance originated to the actual shooting itself," said Officer Alan Brown with the Houston Police Department. "They are being interviewed by the detectives at this time and so we have some pretty good leads right now."
Police say they believe two vehicles left the scene of the crime. They also hope to get clues from the gas station surveillance video.
Authorities say Johnson did have a pistol on the front seat of his vehicle but they don't believe it was fired.
