WAYCROSS, Ga. (AP) — Prison officials say they're investigating the fourth apparent suicide of a Georgia inmate this year.

The state Department of Corrections said in a news release that Justin Stokes was found unresponsive in his cell at Ware State Prison in Waycross just after 1 p.m. Wednesday. The release says prison medical staff tried unsuccessfully to revive him. He was pronounced dead by a doctor at 1:50 p.m.

The agency is investigating, which is standard procedure when an inmate dies in custody.

Stokes was sentenced in 2014 to serve 15 years on assault, battery and animal cruelty charges out of Houston County.

The agency has previously said that three Georgia inmates died by apparent suicide in January.