At about 5:04 a.m. on Oct. 2, a man flagged down an officer on patrol in the 400 block of West Blackhawk Street. The man said someone just pointed a gun at them.
Officers then located the suspect and a foot chase ensued.
The officer pursues Antonio Calmese for nearly two minutes, telling him repeatedly to drop his weapon.
"Drop it! I'll let you go!" the officer is heard saying. "You, you're about to get tased."
After officers engaged with the suspect, one officer deployed his taser twice, COPA said. It appeared the taser did not make contact with the individual.
"Nothing to get shot over! Don't get shot over that gun. Drop it!" the officer is heard yelling.
As the suspect continued to flee, he discharged his weapon in the direction of the officer.
The officer then discharged his weapon, fatally striking the suspect.
A handgun was recovered at the scene, and Chicago police said there were also casings at the scene that did not match the officer's gun.
The officer was taken to an area hospital with minor injuries following the shooting. The injuries were not gunshot related.
According to documents provided by COPA, the responding officer reported an imminent threat, that he was physically attacked with a weapon, and that Calmese did not follow verbal commands.
COPA said the investigation is ongoing.