ANNAPOLIS, Md. (WJZ) -- Joseph Leissler, a leader of the white supremacist Aryan Brotherhood gang in the Maryland Correctional Institution in Jessup, was convicted on murder and gang charges stemming from the killing of John O'Sullivan, a member of a rival gang, Anne Arundel County State's Attorney Anne Colt Leitess said Monday.

Leissler, 52, was convicted on charges of first-degree murder, three gang-related charges and conspiracy to commit first-degree murder.

On Aug. 14, 2016, O'Sullivan, a member of Dead Man Incorporated, was stabbed by three members of the Aryan Brotherhood wielding homemade metal knives--Vincent Bunner, Calvin Lockner and Brian Hare--as he was retrieving the belongings from his cell before heading to the shower.

During the trial, former members of the Aryan Brotherhood said Leissler ordered six attacks on other inmates as a leader of the gang. The attack on O'Sullivan was apparently retaliation for a gang-related assault at a different prison, Leitess' office said.

In 2020, Bunner and Lockner were convicted of second-degree murder for the attack. They were given 30-year sentences on top of the sentences they were already serving.

Hare pleaded guilty to first-degree murder and testified against his co-defendants, prosecutors said.

Sentencing for Leissler is scheduled for Nov. 2. He faces two possible life sentences.