Bryant Grayson, who was 17 at the time of the shooting, faces 3 to 6 years in prison when he is sentenced June 22 by Criminal Court Judge James Lammey Jr.
He faces a mandatory 6-year sentence with no parole for employing a firearm during the commission of a dangerous felony.
The shooting occurred at a Halloween party in October of 2013 at the Whitehaven Recreation & Banquet Center on East Shelby Drive at Tulane.
Investigators said two groups of teenagers attending the party got into an argument and that Grayson pulled a gun and fired several shots into crowd.
Devontay Terry, 18, was shot in the back and the buttocks and was killed.
Grayson was tried on first-degree murder charges, but after four hours of deliberation the jury returned the lesser-included verdict of voluntary manslaughter.
The case was handled by Asst. Dist. Attys. Glen Baity and Sam Winnig.