MERCER, Pa. (KDKA) — State police are investigating the death of an inmate at SCI Mercer.

An inmate, 35-year-old Darl Heverly, allegedly used pieces of a torn bed sheet to strangle his cellmate late Monday night.

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The cellmate is identified as 35-year-old Jason Kelly.

(Source: Pa. Department of Corrections)

According to the facility’s superintendent, corrections officers discovered Kelly unconscious in his cell during a routine check of the prison’s restricted housing unit. The officers and the prison’s infirmary staff tried to resuscitate him.

Kelly was transferred to the Grove City Medical Center where he was pronounced dead.

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He was serving a five- to 10-year sentence for a robber conviction in Allegheny County.

Heverly will reportedly be charged with criminal homicide.

He is set to be arraigned later today.

Heverly is reportedly serving a 29- to 58-year sentence for kidnapping a woman in Union County, robbing her and leaving her tied up in her basement.

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Stay with KDKA for the latest on this developing story.