Maybe it was the deer antlers poking out of the pickup truck’s front grill. Perhaps it was the swastikas festooned on the truck. It might have been that the solitary vehicle was cruising near the Democratic National Committee’s headquarters in Washington, D.C., in the early-morning hours with no visible rear license plate.

Whatever it was that caught the attention of a Capitol Police officer on Sunday night, the strangeness of it all led police to check on the situation and eventually arrest the man inside: Donald Craighead, 44, of Oceanside, California. He told the cops he was “on patrol” and muttered white-supremacist talking points; they found a machete and a bayonet—both forbidden weapons in Washington—in the truck and arrested him.

According to the arresting officers, Craighead was pulled over when officers noticed that his black pickup with antlers attached to the front hood also had no rear license plate—rather, just an American flag in the spot for the plate. Not only is it illegal to drive without a rear license plate, but ad-hoc substitutions such as this are also a common tactic for far-right “sovereign citizens.” He also had painted a red-and-blue swastika on a side mirror and scrawled another swastika on his interior.

So they pulled him over and began questioning the man. He told them he was “on patrol,” though it was unclear what he was patrolling for. He also “began talking about white supremacist ideology and other rhetoric pertaining to white supremacy,” according to the Capitol Police press statement. They took him under arrest after observing the machete and the bayonet inside the truck.

Capitol Police are on edge partly because of plans by some far-right groups to hold a demonstration on Saturday in D.C. protesting the arrests and detention of many of the more than 600 people who have been charged for their roles in the Jan. 6 insurrection at the U.S. Capitol. Police recently reinstalled fencing around the Capitol building in preparation for the Sept. 18 “Justice for J6” rally.

However, police noted that Craighead’s presence might not have been related to those demonstrations. “It is not clear at this point whether he wanted to participate in upcoming demonstrations or whether he has ties to previous cases in the region,” USCP said.

Last month, a man spouting pro-Trump paranoia and threatening that he had a bomb inside his pickup truck created a lockdown situation in downtown Washington. Police shut down the area around the U.S. Supreme Court building near the Capitol until they could negotiate his peaceful surrender.

The planned “Justice for J6” rally Saturday has drawn mixed support from far-right extremists. Several longtime Trump-supporting conspiracy theorists have urged people to attend, including some members of the Proud Boys; however, the Proud Boys themselves are urging their members not to go to the event because they believe their members will be arrested there, as a significant number of them were on Jan. 6.

As analyst Jared Holt observes, the rhetoric around the event is largely hyperbolic, and it is expected to draw neither a large nor a violent crowd capable of another Capitol siege. However, it could be significant in the way that “it lays patchwork or groundwork for those kinds of events to happen in the future in D.C., or maybe in state capitols going forward.”  

D.C. Police say they will be “fully activated” for the event.