Based on the discovery of an abandoned pickup truck just on the other side of the border, authorities think Matthews may have fled to Minnesota, crossing somewhere near Roseau, about 350 miles northwest of Minneapolis. The truck was located on Monday, Minnesota Public Radio reports, and Royal Canadian Mounted Police think it had been there "approximately a week."

Matthews, a member of the Canadian Armed Forces, was exposed as a member of hate groups by an undercover reporter with the Winnipeg Free Press.

The Roseau County Sheriff's Office posted to Facebook warning residents Matthews might be in the area, and to correct rumors swirling that he was wanted for a homicide. In fact, he's a missing person -- albeit a potentially dangerous one -- and has not yet been charged with a crime.

The post instructs people not to approach Matthews, and to instead call local law enforcement or U.S. Border Patrol.

Matthews is a member of a group called The Base, which the Free Press describes as "a secretive network of highly radicalized neo-Nazis that is eagerly preparing for a race war." Matthews' name and millitary service went public after he'd started putting up recruitment posters around Winnipeg, inspiring reporter Ryan Thorpe to infiltrate the group.

In one posting, Matthews, invoking a term leftists slap on Donald Trump supporters, wrote:

"We’re hard targets. They want trumpeter conservatives to protest somewhere so they can mess with them and call them Nazis and get them in legal trouble. We’re real [expletive] Nazis and they can’t do s—- to us but wait for us to put em against the wall."

The undercover reporter observed members of Matthews' group idoloizing mass shooters and serial killers, including the also race-obsessed Charles Manson. Scarier still, the Base is primarily a U.S. organization, and its members are known to admire another neo-Nazi organization blamed for five deaths here.

In their statement about Matthews, the Mounties also encouraged people to call the cops instead of engaging Matthews, saying he "may be under a significant amount of pressure due to this ongoing investigation and the extensive media coverage it has garnered."