The Stillwater prison inmate accused of killing Corrections Officer Joseph Gomm has been charged with murder. According to the criminal complaint, more than 50 witnesses were interviewed and investigators learned that Edward Johnson attacked officer Gomm with a hammer on July 18th. Two homemade knives were also found and officials say one or both were used to stab the officer. Gomm was rushed to Regions Hospital where he died from his injuries. An autopsy showed Gomm died from blunt force trauma to the head, and he suffered two puncture wounds to the chest. Johnson–who was serving a sentence for murdering his former girlfriend in 2002–is now charged with 2nd degree intentional murder. Johnson is set to have his first court appearance Friday morning (10am).