A former US army battalion commander was found guilty on Friday of sexual harassment of a subordinate in what prosecutors hailed as a historic military justice case.

Lt Col Herman West, who was previously stationed at Washington state’s Joint Base Lewis-McChord (JBLM), faced multiple charges over his treatment of a young female officer in his command, KOMO News reported.

The subordinate officer, whose name has not been publicly released, testified in a JBLM courtroom that West harassed her for weeks starting in the summer of 2023.

West’s actions included barging into the women’s bathrooms, making unwanted sexual remarks and repeatedly touching her inappropriately during military outings, KOMO News reported. West also made persistent sexual advances, including telling the woman that he was excited to go on a mission to Indonesia with her so the two could share a hotel room and “get super drunk” and “totally unhinged”.

The woman, who had recently graduated from college and a reserve officers’ training corps (ROTC) program, was initially scared to report West’s behavior because he often bragged about his uncle, former US congressman and Republican party leader Allen West. Herman West had also emailed human resources without the woman’s consent to prevent her from being able to transfer to another position.

However, the woman ultimately reported West after he took off his military shirt and unzipped his pants in front of her as the two were driving back to base from lunch at a local restaurant.

An army colleague later convinced the woman to file a report against West. The woman was also concerned that she would be forced to go on the mission to Indonesia with West and, “if he was bold enough to do that, he was bold enough to do more”, she said, referring to when West unzipped his pants, KOMO News reported. The woman testified that she planned to quit the army after West’s harassment.

West’s punishment after being found guilty is receiving a written reprimand in his military personnel file. He was also fined more than $92,000 after previously facing dishonorable discharge and potential jail time.

In court, West admitted to his actions and apologized to the victim, adding that he had “failed” his colleagues.

His defense team argued that West’s dismissal from the military would harm his wife and children.

West is among the first cases to be prosecuted in front of a court martial after new military justice reforms passed under Joe Biden’s presidential administration. Sexual harassment is now a criminal offense under the Uniform Code of Military Justice (UCMJ).

Military justice advocates celebrated West’s conviction as a historic first step in supporting victims of sexual violence.

The verdict against West “represents a critical milestone in our ongoing fight to end sexual harassment and assault in the military”, said Josh Connolly, senior vice-president of Protect Our Defenders, an organization working to end sexual violence in the US armed forces. “I commend this brave service member for her extraordinary courage in coming forward to hold Lt Col West accountable.

“This case, one of the first prosecuted under new sexual harassment criminal offense laws, sends a clear message that sexual misconduct will not be tolerated in our armed forces.”