ST. CHARLES COUNTY, Mo. – An incarcerated person died in St. Charles County Jail early Tuesday morning, prompting a joint investigation by county police and the county medical examiner’s office.

According to St. Charles County Corrections Director Dan Keen, the individual arrived at the jail on May 22 and was detoxing from fentanyl and other drugs.

Around 3:30 a.m. Tuesday, the individual got out of his bunk to use the bathroom in his cell. When corrections officers made their routine wellness checks, they noticed he’d not returned to his bunk and found him unresponsive.

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Newly incarcerated individuals are checked every 15 minutes around the clock, Keen said.

Corrections officers and medical staff attempted to resuscitate the man with CPR and the AED machine until EMS arrived at 4:10 a.m. The man was pronounced dead at the jail at 4:45 a.m.

Keen claims no contraband was found and there was no sign the individual had obtained drugs while at the facility. The man was in a single cell by himself and there were no signs of foul play.

Authorities have not released the 39-year-old’s name, pending notification of family members.