A former army reservist and two other alleged members of a violent neo-Nazi group discussed "executing" a police officer to steal his weapons and "committing targeted acts of violence" at Monday's pro-gun rally in Virginia, according to documents filed Tuesday in a Maryland court.

Patrik Mathews — who went missing for several months after police raided his home in Beausejour, Man. — also made a video calling for violent revolution and the derailing of trains, expressed hopes of building a network for others with similar views, and predicted an upcoming civil war, according to a sweeping document filed by federal prosecutors.

The document, which cites hidden camera footage, lays out arguments for keeping Mathews and the two other men behind bars. All three were arrested last week.

It also reveals the lengths Mathews, Brian Mark Lemley Jr., and 19-year-old William Garfield Bilbrough IV planned violence similar to what was seen at a rally in Charlottesville, Va., in 2017, in which one person was killed and dozens others injured.

"We can't let Virginia go to waste, we just can't … Virginia will be our day," Mathews stated, according to the detention memo.

The conversations were captured in December and January on a hidden camera and microphone installed by law enforcement in the apartment where Mathews and Lemley, a 33-year-old former U.S. army cavalry scout, were living.

They were installed after a Dec. 13 secret search of the apartment, in which officers found flyers promoting The Base, communication devices, empty rifle cases and "go bags" — with ready-to-eat meals, knives and the items needed to build an assault rifle.

They also found videos of Mathews talking about his journey into the United States, using violent anti-Semitic and racist language.

In the video, in which Mathews wears a gas mask and has his voice distorted, Mathews says: "The time for talk has ended … If you think politics is a solution, you are a damn fool … It is the system that is fomenting violent revolution, not us, and they shall now reap what they have sown."

He goes on to say people can either prepare for collapse or bring it.

"Derail some f-cking trains, kill some people and poison some water supplies … If you want the white race to survive, you're going to have to do your f-cking part."

At one point, Mathews says he wishes he had set explosive devices for the RCMP team that raided his home and took his guns in August.

"In all honesty, I could really wish they f-cking all started searching my place, accidentally trip a pin, and, boom, and the whole house goes boom. Boy, wouldn't that be terrible, a bunch of f-cking RCMP search experts got f-cking exploded," he said, according to court documents.

Brian Lemley, second from the left, and William Bilbrough, kneeling, allegedly attended a Base training camp in Georgia in August 2019. (U.S. Attorney detention memo)

Mathews and Lemley are facing a number of charges , including transporting a firearm to commit a felony. Bilbrough is charged with "transporting and harbouring aliens."

They were all scheduled to appear in court Wednesday for detention hearings, but Lemley has since waived his right for a detention hearing.

Mathews' lawyer would not comment when asked if he was proceeding with the hearing. Bilbrough's lawyer said they intend to proceed as planned.

The latest document fills in some of the blanks of Mathews' alleged activities since he disappeared from his home in Beausejour, Man., at the end of August 2019, shortly after he was first accused, by a reporter with the Winnipeg Free Press, of being a recruiter for The Base.

The document says after illegally crossing the border near Piney, Man., Mathews met Lemley and Bilbrough in southern Michigan. Police followed their movements using Google location data, cell phone location data and recorded calls.

In mid-September, Lemley drove Mathews to the property of a Base member in Georgia, identified by an undercover FBI agent as a headquarters and training camp for the group.

Tuesday's document does not name the house's owner, but previous court filings state that a man presumed to be Mathews stayed at Luke Austin Lane's property for months last year.

Lane was among three Georgia men arrested last week , charged with conspiracy to commit murder and being part of a criminal gang.

Mathews, left, and Lemley bought approximately 150 rounds of ammunition at a store in Delaware on Jan. 1. This is surveillance video from the store. (U.S. Attorney detention memo)

During his time in Georgia, Mathews said he "only exists for the white revolution now," according to the document. He wanted to remain a "ghost" and oversee safe houses for other Base members and, when there were enough of them, start committing attacks.

Mathews also searched the internet for information about Atomwaffen Division, another neo-Nazi group; building AR-15 assault rifles; and stories about himself, prosecutors allege.

Between Oct. 30 and Nov. 2, he was joined at the Georgia location by Lemley, Bilbrough, and other alleged Base members. Lemley and Bilbrough had bought about 1,500 rounds of ammunition while they were in Georgia. Separate affidavits have described about a dozen members of the group — including an undercover FBI agent — attended this meeting, which included firearms training, medical training and a pagan ritual with the sacrifice of a goat.

At the end of that gathering, the trio returned to Maryland. Lemley and Mathews rented an apartment in Newark, N.J.

One day before their arrests, Lemley told Mathews that "there cannot be no trust among a group of murderers," court documents say.

"I cannot trust you to keep my murdering secrets. Not under threat of 30 years in jail and torture. Why should I trust you?" Lemley asked.

Monday's rally in Richmond, Va., attracted tens of thousands of people and, although there was some tension between different groups, ended without violence.

Military investigating

Mathews was released from the Canadian Armed Forces (CAF) at the end of August.

The Department of National Defence says it can't comment on specific cases, but said in a statement that as of Dec. 5, 2019, investigations involving 15 CAF members have resulted in measures ranging from counselling, warnings and probation to other disciplinary measures.

Twenty-one members are no longer serving in the CAF; three were released because of hateful conduct. Other investigations are ongoing.

The military ombudsman is currently reviewing racism and white supremacy in the CAF. Defence Minister Harjit Sajjan said Tuesday he's hoping for an update on that review soon.

"The vast majority of Canadian Armed Forces personnel are absolute professionals … who want to make sure that the organization that they join, the uniform that they wear, upholds those values," he said. "They're not going to allow the few to take that away from them."

Sajjan and Public Safety Minister Bill Blair were in Winnipeg for Liberal cabinet meetings. Blair declined to say if Canadian authorities are also investigating The Base.

"I'm not going to talk about any ongoing investigation or the sharing of intelligence information except to confirm that we do work very closely with U.S. authorities and are very vigilant in addressing any potential risks to Canadians," he said.