A Flathead Valley man with a criminal record dating back to the time he was a juvenile added another criminal conviction to his record while he was incarcerated.

Jack Allen Mellem, 31, was sentenced Thursday for assault on a peace officer, involving head-butting a jail guard in the face. Mellem was being held in the Flathead County Detention Center for violating the parole conditions of a previous conviction when the assault took place.

The inmate was reportedly in the process of being transported from the shower area back to his cell on Nov. 12, 2017 when the assault occurred. Mellem reportedly head-butted the guard after complaining his hand cuffs were too tight, according to the police report.

The detention officer who was head-butted had to seek medical attention for a broken nose, according to another officer’s report.

A pre-sentence investigation prepared by the Department of Corrections Adult Probation and Parole Department outlines a slew of transgressions during Mellem’s latest incarceration, including threatening to kill the jail guards, and his cellmates while he was reportedly coming down from opiates.

The inmate’s mental health was discussed during his sentencing. He is reportedly on an anti-psychotic medication but was cleared fit to proceed.

Flathead District Court Judge Dan Wilson ordered Mellem to five years in Montana State Prison for the assault charge. This sentence will run simultaneously with the another five-year sentence involving the theft of a running vehicle from a man’s driveway.

The court recommended Mellem be placed in the NEXUS program, which provides treatment for drug addiction, when he is paroled.

Reporter Breeana Laughlin can be reached at 758-4441 or blaughlin@dailyinterlake.com.