Baltimore City Police say they are investigating the shooting of a would-be carjacker in southwest Baltimore.

Police were called around 3:45 p.m. Wednesday to an area near Washington Boulevard in Carroll Park, where three young men had approached a man sitting in his car.

Police said the assailants tried to carjack the victim.

Police said when one of the assailants pulled out what appeared to be a handgun, the victim pulled out a gun and shot the assailant once. The assailant, a 13-year-old boy, is in critical condition. The firearm he possessed was a replica, police said.

The two other assailants fled.

Police said the victim is a 73-year-old former Baltimore City police officer, who retired in 1974. Police said he currently works as a private investigator and has a handgun permit from the Maryland State Police for the weapon.

Police say the man  remained at the scene.