A former U.S. Marine linked to white supremacy who allegedly conspired to commit mass murder and sexual assault entered guilty pleas in federal court Tuesday for his role in a scheme to set up illegal firearm purchases through a New York police officer.

Former Cpl. Matthew Belanger, 25, entered a plea of guilty before U.S. District Judge Jill A. Otake to one count of conspiring to make a false statement to a federal firearm licensee and one count of making a false material statement during the purchase of a firearm.

Belanger joined the Marines in August 2018 and was stationed at Marine Corps Base Hawaii in Kaneohe from October 2019 to May 2021.

Belanger, scheduled to be sentenced by Otake at 9 a.m. June 6, faces up to five years in federal prison and a fine of up to $250,000 plus three years of federal probation on the first count and up to 10 years and a fine of up to $250,000 plus three years of federal probation on the second count.

Belanger’s Atlanta attorney, Katryna Lyn Spearman, did not immediately reply to Honolulu Star-Advertiser requests for comment. Assistant U.S. Attorney Craig S. Nolan declined comment.

In exchange for his guilty pleas, the U.S. Department of Justice agreed to dismiss a third count of making a false statement of required information to a federal firearm licensee.

According to the plea agreement filed Tuesday, during April and May 2020, Belanger entered into an agreement using a straw man that required a police officer from Long Island, N.Y., to buy a Luger 9-mm pistol for Belanger.

On March 23, 2019, court documents show, Belanger made the following statement in a conversation via Facebook direct message: “Okay so [officer] is down for being my gun plug…I showed him what the safe act has done to guns and what he is capable of getting…So if you boys have any ideas for guns he can get em and when we move have em ready to go for us.”

When the gun was purchased on May 20, 2020, by someone identified by federal authorities as “Associated 1,” Belanger was in Hawaii while the police officer was at Fred’s Gun Shop in Port Jefferson, N.Y., according to federal court documents. Both Belanger and “Associate 1” knew using a straw man to buy a gun was a federal offense. On April 21, 2020, Belanger texted “Associate 1” to buy the gun and sent him $975 via Cash App to complete the purchase.

While serving at Marine Corps Base Hawaii, Bel­anger allegedly plotted mass murder and sexual assault to “decrease the number of minority residents” in the United States as part of his membership in a far-right neo-Nazi group called Rapekrieg.

Belanger has not been charged with crimes related to his alleged membership in the group.

He received an “other than honorable” discharge from the Marine Corps in May 2021 for extremist activity after he was investigated by the military and the FBI. He left Hawaii and moved back to New York.

Federal prosecutors allege there is also “substantial evidence” that he was planning an attack on a synagogue in New York, has “engaged in live exercises to practice such an attack” and “made plans to engage in widespread homicide and sexual assaults to decrease the number of minority residents in the United States.”

A July 14 court memo by an FBI agent with Joint Terrorism Task Force Pacific also alleges Belanger intended to rape “white women to increase the production of white children.” On Oct. 20, 2020, Marine Corps and FBI officials searched his barracks and seized a laptop and two cellphones.

FBI agents allegedly recovered “1,950 images, videos and documents related to white power groups, Nazi literature, brutality towards the Jewish community, brutality towards women, rape, mass murderers,” along with “violent uncensored executions and/or rape” and “previous mass murderers such as Dylan Roof.”

Prosecutors say they also found “instructional documents relating to building explosives and/or illegal firearms” and “communications related to illegally obtained firearms.”

A Rape­krieg manifesto cited by federal prosecutors speaks approvingly of “rape ideology” as an “effective tool” against the group’s supposed enemies.

Belanger also allegedly created a Twitter account of a fictitious gay Jewish man named “Israel Shillingstein,” which he told fellow Rape­krieg members was meant to make derogatory statements about Black people in order to generate racial animosity between groups.

In one of the communications investigators obtained regarding the alleged plot of attack against the synagogue, one of Belanger’s associates said, “before you do this, delete all your social media, destroy your hard drives and any evidence that would suggest your motive if you get caught,” prosecutors said.