Mob guys don't take civilians out on purpose. Who is going to approve that? Hey if it was a failed hit on the mobster then that is on the shooter.
You honestly think if a civilian threatened to put some big mob boss away they wouldn't at the least get threatened? Yes as time went out it was frowned upon. But in the era we of the murders we seem to be discussing anyone was fair game. If you were high enough up the ladder and one civilian stood in your way you better believe someone like Lucky would have had that person buried.
