Investigators say the two men knew each other before the confrontation, but it's unclear what led to the argument.
Mancilla turned himself in to police just hours after the shooting. The trial is expected to last two weeks once testimony begins.
Investigators say the two men knew each other before the confrontation, but it's unclear what led to the argument.
Mancilla turned himself in to police just hours after the shooting. The trial is expected to last two weeks once testimony begins.