Police said shortly before 4:30 p.m. they were called to a home in the 200-block of Fern about an armed man. When they arrived, a man left the home with a knife in hand.
The man confronted officers outside in a nearby yard, and during the confrontation police opened fire on him. He was taken to a local hospital where he was pronounced dead.
The man was identified as Jack Murray, 24, of Chicago, according to the Cook County Medical Examiner's Office.
Murray's family said he was suffering a diabetic episode and needed help.
"He was challenged by health issues, being type one. It impacted him physically and was an emotional challenge," said his aunt Liz Belcaster.
The family's attorney said he believes Murray realized he was in need of help and called 911 himself. The family said he had done that in the past, and police should have been aware of their history with him at the home.
"It is utmost importance getting emotionally disturbed person the assistance they need," said attorney Antonio Romanucci.
With Murray's mother weeping quietly in the background, the family's attorney said he wants answers from police including the 911 call and any body or dashcam video that is available. Romanucci said Murray posed no threat, and police should have tried to de-escalate the situation rather than fire at him.