Chicago police shot and killed a man in the Old Town Triangle neighborhood before midnight Saturday night

Chicago police shot and killed a man in the Old Town Triangle neighborhood before midnight Saturday night, according to police and a union spokesman.

The off-duty officer lives in the area and saw a man on the porch of a vacant apartment about 11:30 p.m., Fraternal Order of Police Spokesman Patrick Camden said. 

The officer called 911 twice during the incident, Camden said.  He called out to the man to see what he was doing and the man replied "you don't want no part of me," Camden said. 

The man had a bag or sack over his shoulder and his hand on his waistband, Camden said, but repeatedly ignored the officer's commands to come down after he identified himself as an officer. 

"So he comes downstairs and the officer says, 'Let me see your hands.' The guy keeps telling him, 'You don't want no part of me,'" Camden said. "And a neighbor is standing there and tells him, 'He's a police officer, he's a police officer, show him your hands.'" 

The man turned down a gangway and started to walk away but the officer told him there was no way out of that gangway, Camden said. 

The man, in a dark gangway, grabbed his waistband and threatened to kill the officer while continuing to ignore the officer's demands to show his hands, Camden said. 

The officer opened fire after the man grabbed his waistband, striking the man, Camden said. He died at the scene, and the officer was not injured. 

"It was pretty loud to be heard inside his apartment, so it had to be super loud for it to be heard," said Taimur Farasat, 27, who was at a friends house on Lincoln Avenue when he heard two gunshots. 

The Chicago Police Department released a statement about 4 a.m. confirming Camden's account of the shooting. 

It's not clear whether a gun was recovered at the scene. As of 5 a.m., the Cook County medical examiner's office wasn't sure who the dead man was, but said he was in his 20s and pronounced dead at the scene about 12:20 a.m.