A federal jury in Chicago on Monday convicted a notorious gang boss who, prosecutors said, used ruthless violence and fear to profit off the West Side drug trade for 20 years.

Four years after he and 10 others were charged in a sweeping federal racketeering indictment, jurors returned a unanimous guilty against Labar “Bro Man” Spann, the leader of crew known as “The Outlaws,” a group born out of the larger Four Corner Hustlers gang.

“He is a smart, ruthless and manipulative gang leader,” Assistant U.S. Attorney Timothy Storino said during the closing arguments of the eight-week trial at the Dirksen Federal Courthouse. “He is a person who kills, he robs, he extorts and he intimidates others all in furtherance of his gang, the Four Corner Hustlers, and he has done it for over two decades.”

pann was found guilty of all four counts against him: racketeering conspiracy, extortion and two other counts of murder in the aid of racketeering, which carry a minimum life sentence. His sentencing was scheduled for March 2022.

The charges linked Spann to six killings between 2000 and 2003. Jurors, however, found that Spann was not responsible for two of the murders included in the charges: those of Carlos Caldwell and Levar Smith, both of which occurred in 2000.

Spann — who survived at least two shootings, including one that left him paralyzed from the waist down in 1999 — and the others were charged in September 2017, though all of his co-defendants pleaded guilty before trial. Among them was Sammie Booker, a gang enforcer who cooperated with prosecutors and said that he helped carry out several murders at Spann’s direction.