An inmate in the custody of the Arizona Department of Corrections in Tucson has died, the possible victim of a homicide, the department said Saturday.

Christian Frost, 38, was pronounced dead Friday at the state prison here after receiving medical treatment. Frost, who was convicted in Maricopa County, was serving 26 years for manslaughter, flight from law enforcement and aggravated assault.

Officials say the investigation is being conducted by the department's criminal investigations unit.