PORT ORCHARD — Following an autopsy, the Kitsap County Coroner determined that Stephanie Ann Melton, who was found unresponsive Monday in her Kitsap County Jail cell, had later died at St. Michael Medical Center due to peritonitis caused by a ruptured gastric ulcer.

The coroner’s office announced the determination Thursday afternoon in a news release.

The 40-year-old Port Orchard woman had been charged in Kitsap County Superior Court Dec. 10 with a charge of controlled substance homicide following an investigation by Port Orchard Police that determined she contributed to her 11-year-old daughter’s death by giving her the drug fentanyl at home. Melton reportedly had smoked an opioid substance in the presence of her daughter.

She pleaded not guilty to the charge and was being held on $750,000 bail.

Kitsap County forensic pathologist Dr. Lindsey Harle performed the autopsy on the woman, whose manner of death was classified as “natural.”