Mates was a bouncer at the Waterbury bar.
Police said Nerbonne, 21, of Meriden, handed the gun to West, who pulled the trigger. Officers charged Nerbonne with a single count of aiding and abetting in Mates’ murder.
Mates, 27, died at Saint Mary's Hospital shortly after the shooting.
West was a student at Maloney High School and a counselor at the boys and girls club. He’s being held on a $2 million bond.
He returns to court next month.