A grand jury has charged an inmate with first-degree murder in the death last month of a Stillwater prison corrections officer.

Convicted murderer Edward M. Johnson, 42, who was already serving time for a previous slaying, had been charged on Aug. 2 with intentional second-degree murder and second-degree assault in connection with the attack on Joseph Gomm in a vocational building where offenders were offered welding classes.

He is now charged in Washington County District Court with first-degree premeditated murder and first-degree murder of a corrections officer. A first-degree murder conviction would keep Johnson in prison for life without the possibility of parole.

Johnson, who was moved to the more restrictive Oak Park Heights prison after the killing of Gomm on July 18, was scheduled to appear in court Friday.

The enhanced charges come in the same week that two others serving long sentences at Oak Park Heights were charged in Washington County with felonies in connection with violent attacks on corrections officers.

Gomm, 45, of Blaine, was bludgeoned with a hammer and stabbed, suffering substantial injuries to his head and face and two puncture wounds to his chest, according to the initial charges.

Johnson was to have been released from prison in late 2022 and then serve the balance of his sentence for a 2002 murder on supervised release. However, a conviction for Gomm’s death could keep him behind bars for the rest of his life.

Johnson has a long history of violence that continued into his incarceration. At the time of Gomm’s death, Johnson was serving a 29-year term for fatally stabbing his 22-year-old roommate, Brooke Thompson, while her 5-year-old daughter was nearby in their Bloomington home.

Later that same year, while in the Hennepin County jail during his trial, Johnson assaulted a deputy. He pleaded guilty to fourth-degree assault and was given a 10-month term.

In prison he has racked up at least 1,695 days in segregation for numerous offenses, including 540 days in connection with a prison fight in July 2004, authorities said.

Johnson was most recently sentenced to segregation in June 2016. Since then, he had demonstrated “relatively good behavior” and been allowed to work in the prison industrial building, said Corrections Commissioner Tom Roy.

Charges in other assaults

In late June, an Oak Park Heights inmate slashed the face of a corrections officer, saying he wanted to make sure the officer would never forget him, according to charges.

Joshua L. Smith, 28, serving a long sentence out of Benton County for aiding and abetting murder, was charged this week with first-degree assault in connection with the attack.

The officer was left “bleeding profusely” from his head and neck, the charges said. The weapon was a toothless comb with a razor blade attached, according to the complaint.

Smith told investigators that he was angry at the officer and “want[ed] to permanently scar him so [he] would remember” him.

Smith was serving time for the December 2013 killing of Jamie R. Wylie of Foley, Minn., and was more than 19 years away from being released.

In March, eight Oak Park Heights inmates brawled with five officers in a recreation area, according to the charges against one of the inmates, 34-year-old Dustin A. Vaughn.

Four of the officers suffered head injuries and one had a broken finger.

Vaughn has been serving a life term since 2003 for first-degree murder in the beating of 31-year-old Jeffrey Barrett in Chippewa County.

An Associated Press analysis of Corrections Department data shows 186 inmate assaults on employees in the most recent fiscal year, up from 114 the previous year. Assaults that caused harm jumped from 12 to 30, and assaults with weapons rose from one to seven.