SIOUX FALLS, S.D. (MITCHELLNOW) Authorities say a South Dakota State Penitentiary inmate has died of an apparent suicide. Prison officials report 57-year-old Keith McLain was found unresponsive in his cell on September 22nd. He was taken to a nearby hospital, where he was pronounced dead. McLain had been serving time on a Minnehaha County conviction for second-degree rape. The Department of Corrections has not released any more details. For more crime stories from MitchellNow.com, click here.