CHICAGO (CBS) — Chicago police will not charge a gun owner for using it to stop a robbery in a Southwest Side business Saturday.

The man, a civilian, shot and killed the would-be stick up man. CBS 2’s Mike Parker has the latest.

Police say 55-year-old Reginald Gildersleeve went into a Gage Park neighborhood currency exchange Halloween evening wearing a mask. They say he was not trick or treating.

Inside, he allegedly pulled out a paintball gun and announced a robbery. When he confronted a customer, the customer pulled out a real gun and shot Gildersleeve dead.

“That doesn’t mean that you can be Mr. Hero or that you can shoot a man multiple times,” said Gildersleeve’s stepson Igbinosa Oronsaye. “But to shoot him over and over, that’s not our American rights.”

Police say the shooter has not been charged. Why? He had a concealed carry permit and a valid FOID card, with no criminal record. They say he acted in self-defense and there were witnesses and surveillance video.

“There would be nothing to charge him with,” said CBS 2 Legal Expert Irv Miller. “He shot the guy while the guy was committing a felony. He had permits for the gun. There’s no charge on the books that would cover that situation.”

Miller says the case is a prime argument for those who advocate everybody carrying guns.

“Hey listen, if somebody had a gun and they go into a store and there’s a robbery, they are there to protect everybody,” Miller said.

While many are no doubt praising the shooter for his quick action, the Southwest Side resident is said to be shaken by the incident. He wants to remain anonymous because, sources say, he fears he may be targeted for retribution.