FORT LEAVENWORTH, Kan. -- A former Navy officer who served 16 years at Fort Leavenworth federal prison after hiring a hit man to kill his wife died less than 30 days before he was due to be released.

Navy Lt. Commander Michael Fricke confessed to hiring two hit men to kill Roxanne Fricke in 1988.

Army officials said there was a brief altercation between Fricke and another military prisoner on a secured recreation field at the U.S. Disciplinary Barracks at 2 p.m. July 24 while several inmates were playing sports.

Army officials said Fricke was struck several times with a baseball bat before guards subdued the attacking inmate.

Fricke was taken to an area hospital and died late Thursday night after his family authorized doctors to take him off life support, Army officials said. The alleged assailant has been sent to a secured area of the prison and the incident is under Army investigation.

In 1994, Fricke was sent to Fort Leavenworth. Fricke was sentenced to 30 years in prison While he was sentenced to 30 years in prison. The family got a letter announcing Fricke would be released in August near Daytona Beach, where his son now lives.