Authorities in Alabama are investigating the death of an inmate who was found unresponsive in the booking area of a county jail.

The Limestone County Sheriff’s Office told news outlets that inmate Randall McCafferty was declared dead at a hospital Monday.

Records show the 57-year-old was arrested Sunday and charged with driving under the influence.

The sheriff’s office said in a statement that he’d been hospitalized for four hours before being taken to jail that night.

His body has been sent for autopsy and a state law enforcement official said the Alabama Bureau of Investigations is reviewing the death at the sheriff’s request. Sheriff Mike Blakely said it isn’t being considered suspicious.

McCafferty was being temporarily housed in the jail’s booking area. The sheriff’s office says he was under constant observation.