CHICAGO (CBS) — Detectives were questioning a person of interest Wednesday night in the killing of a 1-month old boy last week in Englewood.

About 2 p.m. on Dec. 7, officers were called to assist paramedics treating the unresponsive infant inside his home in the 6600 block of South Racine, according to Chicago Police and the Cook County medical examiner’s office.

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Timothy Harmon was taken to St. Bernard Hospital, where he died at 2:39 p.m., authorities said. An autopsy ruled his death a homicide by child abuse.

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Police said Wednesday night that Area South detectives were questioning the person of interest. No charges had been filed as of 8:30 p.m., according to police, who initially said the boy showed no obvious signs of trauma.

The state Department of Children and Family Services — which had no prior contact with the family — was also investigating, an agency spokeswoman said.

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