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.

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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.

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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.

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

Brandon Weigel