It all happened Friday morning at Chicago and Homan avenues on the West Side.
Police say that Robert Cary and Jimmy Townsend approached an armored guard as he made a pick-up at the Family Dollar store.
One man reportedly put a gun in the guard's face, the other stuck a gun in his back.
The guard and the armored truck driver responded by shooting both suspects. Townsend died.
Eveb though Cary didn't pull the trigger, he's charged with Townsend's murder, attempted armed robbery and unlawful possession of a weapon.