BALTIMORE (AP) — Baltimore police say an off-duty security guard foiled an armed robbery attempt when he shot his assailant.

Police say the man told officers early Saturday morning that a man pointed a gun at him during a robbery attempt in Northwest Baltimore. The off-duty guard drew his gun, and the assailant opened fire. The guard returned fire, wounding his attacker in the shoulder.

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Police located the 20-year-old suspect a short time later. He’s being treated for a gunshot wound to the shoulder.

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The security guard was not injured. Police continue to investigate the shooting.

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