CHICAGO (STMW) — An off-duty Chicago Police sergeant fatally shot a man Sunday evening in the Mount Greenwood neighborhood after he watched the man shoot another person in a Southwest Side bar.

The sergeant watched the 45-year-old man shoot another male about 6:30 p.m. in a business near 111th Street and Spaulding Avenue, according police and the Cook County medical examiner’s office. Officers could be seen investigating inside Blackthorn Pub, at 3300 W. 111th St.

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The sergeant pulled out his gun, identified himself as a police officer and ordered the shooter to drop his weapon, police said.

The man ignored the sergeant and instead pointed his weapon at patrons of the business and at the sergeant, authorities said. The sergeant then opened fire.

The man was pronounced dead at the scene at 6:49 p.m., the medical examiner’s office said. His name was not released Sunday night pending notification of his family.

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The male whom the gunman shot, whose exact age was not immediately known, was taken to Advocate Christ Medical Center in Oak Lawn; his condition was not available, police said. The sergeant was not injured.

Police said the gunman’s weapon was recovered at the scene.

The Independent Police Review Authority is investigating the shooting, spokesman Larry Merritt said.

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(Source: Sun-Times Media Wire © Chicago Sun-Times 2014. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)