BOISE, ID – A 32-year-old inmate serving time for prior felony convictions has been sentenced to life in prison for a violent assault on a correctional officer at the Idaho Maximum Security Institution.

Elijah Joseph Grant St. Onge received a life sentence with 10 years fixed from Ada County District Judge Lynn Norton. The sentence, handed down Wednesday, will run consecutively to St. Onge’s existing prison term for convictions out of Kootenai County, including lewd and lascivious conduct with a child and robbery.

The sentencing follows a March 2024 incident in which St. Onge used a homemade weapon to carry out an unprovoked attack on a correctional officer, resulting in defensive injuries. He was convicted of aggravated battery by a jury in April 2025. St. Onge later admitted to being a persistent violator, which under Idaho law prompted a sentencing enhancement due to his prior felony record.

“This was a calculated and dangerous attack on a correctional officer who was simply doing his job,” said Ada County Prosecutor Jan Bennetts. She credited the Idaho State Police and Department of Correction staff with thoroughly investigating the case, and thanked the trial team and jury for their efforts.

The case was prosecuted by the Ada County Prosecutor’s Office and investigated jointly by ISP and IDOC.