CHICAGO (CBS) — An autopsy has been deemed inconclusive for a 17-year-old boy who died in police custody, after being arrested for possession of heroin on the city’s West Side.

The teen, identified by the Cook County Medical Examiner’s office as Mark Haynie — was arrested Tuesday night in the 900 block of North Trumbull Avenue, police News Affairs Officer Daniel O’Brien said.

Haynie was being held at the Harrison District police station, at 3151 W. Harrison St., when he was found unresponsive at 5:15 a.m. Wednesday.

Police said he was taken to Mount Sinai Hospital, where the Medical Examiner’s office said he was pronounced dead at about half an hour later.

A Wednesday autopsy on Haynie, of the 1000 block of North St. Louis Avenue, was inconclusive pending results of a toxicology test, according to the Medical Examiner’s office.

The Sun-Times Media Wire contributed to this report.

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