Jason M. Simpson, 26, of Indianapolis was pronounced dead at 4:50 a.m. Monday at Putnam County Hospital, a release from Putnamville Correctional Facility Public Information Officer Alisia Lawrence said.
Officers from Putnamville's Internal Affairs Division and the Indiana State Police are investigating Simpson's death.
"The cause of death will not be determined until an autopsy has been completed by the Vigo County coroner," Lawrence's release said.
Simpson was convicted of Class B felony armed robbery in November, while already serving a sentence for a December 2002 charge of Class C felony carrying a handgun without a license. He was sentenced in January on two additional counts, Class D felony resisting law enforcement and Class A misdemeanor possession of marijuana/hashish. He received a one-year sentence for each of those counts.
The Indiana Department of Corrections Web site lists Simpson's earliest possible release date at Aug. 17, 2009. Lawrence said in her release Simpson's projected release date was Nov. 4, 2010.
"Any loss of life is a tragic event. My sympathies go out to Mr. Simpson's family," said Putnamville Superintendent Michael J. Osburn.