A Washington state man who was involved in an armed brawl at a contentious protest in downtown Portland over the weekend was also charged, along with his son, over his presence during the attack on the Capitol in Washington DC on 6 January.

Jeffrey Grace’s ongoing participation in far-right street politics since January – which has included trips to the southern border – indicates that widespread charges against those involved in the Capitol attack have not deterred at least some militant pro-Trump supporters from further direct actions.

Grace, 62, of Battle Ground in south-west Washington, was captured by a photographer at the scene of the clash, which involved antifascists on one hand, and on the other armed rightwing demonstrators.

Some of thedemonstrators appeared to be members of the Proud Boys, which is designated a hate group by the Southern Poverty Law Center and is banned as a terrorist group in Canada.

The rightwingers, including Grace, had assembled in defense of a religious service led by Artur Pawlowski, a Polish-Canadian preacher whose events have long attracted antifascist counterprotests in Canada and abroad.

Saturday’s service was reportedly disrupted by antifascists, which led to street fighting involving pepper spray, paintball guns, batons and other weapons. One of the far- right group was captured by a reporter on camera brandishing a long gun in the streets.

Grace was captured leaving the scene of the brawl in the back of a truck, holding a baton.

The next morning on his Instagram account, he admitted that “I went down in support of a pastor’s right to speak”, and that “we did perimeter security”.

At another point in the video, Grace said “people say you can’t fight Antifa with these”, held up his fists, and continued “well guess what, you can”.

Grace uses his social media channels to promote his web store, where he sells merchandise including T-shirts featuring images of the Capitol over the slogan “OUR HOUSE”.

Federal charging documents alleged that federal agents found in the trash folder of Grace’s cellphone “a “selfie-style” video that depicts him and an individual believed to be his son Jeremy outside the USCapitol building, both repeatedly saying: “Our house”.

In local media interviews, Grace has admitted to the central charge in the document: that he unlawfully entered the Capitol building. Grace did not respond to several Guardian attempts to contact him.

Pawlowski, the preacher, has attracted significant controversy in his home province of Alberta after adopting a range of far-right political positions. He once attributed Alberta floods to divine displeasure over homosexuality and he has participated in tiki torch anti-lockdown rallies in Calgary.