WASHINGTON COUNTY, Minn. - A grand jury in Washington County has indicted an inmate accused of killing a guard at the Stillwater Prison last month of first-degree murder charges.

The jury returned an indictment against Edward Muhammad Johnson on charges of first-degree premeditated murder and first-degree murder of a prison guard.

Johnson was previously charged with second-degree murder in the death of corrections officer Joseph Gomm.

Corrections Officer Joseph Gomm.jpg
Corrections Officer Joseph Gomm was attacked and killed by an inmate at the Stillwater Prison on Wednesday. (Photo courtesy: www.ODMP.org)

Gomm's death marks the first time a corrections officer has been killed in the line of duty in Minnesota.

According to the charges, Johnson struck officer Gomm repeatedly in the head and face with a hammer that he checked out from the "M Shop," a workshop on the third floor of the correctional facility where inmates can take welding classes.

A shop foreman at the prison told investigators he was approached by an inmate who told him that Gomm needed help and when he went into the "M Shop," he saw Johnson striking Gomm in the head with the hammer. The foreman ordered Johnson to stop and called for help on his radio.

He said that's when Johnson stopped and began walking towards him, while swinging the hammer at him.

Fearing for his life, the foreman told investigators he left the shop and ran to a nearby stairwell. Johnson then shut the door leading from the stairwell into the shop and barricaded it shut, according to the charges.

Several inmates reported to investigators that they saw Johnson running around the shop, without a shirt on. Johnson then opened a back door to the shop, activating an alarm, charges state. When correctional officers reached Johnson, he put his hands up and told them he was surrendering. Johnson was then taken into custody.

According to the charges, Johnson checked the hammer out when he reported for work the afternoon of July 18. Officers found the bloody hammer near where Johnson eventually surrendered. They also found two homemade knives, which were used to stab Officer Gomm during the attack.

The charges do not detail Johnson's motive.

Johnson had been serving a nearly 29-year sentence for murdering Brooke Elizabeth Thompson, a former girlfriend he lived with in 2002. According to the Department of Corrections website, Johnson was scheduled to be released in December 2022 after serving two-thirds of his sentence, which is standard in Minnesota.

While being held in the Hennepin County Jail on that murder charge, Johnson also attacked a jail guard on Dec. 15, 2002.