image sourceGetty Imagesimage captionEnrique Tarrio has led the far-right group since 2018
The leader of the far-right Proud Boys group has been sentenced to nearly six months in jail for burning a stolen Black Lives Matters flag in December.
Enrique Tarrio, 37, pleaded guilty in July to two crimes: burning the flag and bringing two high-capacity gun magazines into Washington DC.
Appearing through video in court on Monday, Tarrio apologised and said there was "no excuse" for his actions.
He will report to jail on 6 September to begin his 155 day sentence.
Prosecutors said that Tarrio and other members of the Proud Boys removed the banner from the historically black Asbury United Methodist Church on 12 December and set it ablaze.
The incident was a part of a pro-Trump demonstration in protest of Joe Biden's election win.
Several days later, Tarrio admitted to participating in the banner's burning in an interview with the Washington Post.
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While Tarrio acknowledged his actions were "wrong" in Monday's hearing, DC Superior Court Judge Harold Cushenberry said his remorse was "wholly unconvincing".
Mr Cushenberry added that he believes Tarrio "clearly, intentionally and proudly crossed the line from peaceful protest and assembly to potentially violent conduct".
The mostly peaceful demonstrations in December ended in isolated scuffles after counter-protests began. Police said that more than three dozen people were arrested and four churches were vandalised.
Local police took Tarrio into custody on 4 January, just two days before the Capitol Hill riot on 6 January. Police found weapon magazines in his car during a traffic stop – which led to the second charge.
Ahead of the riot, Tarrio said on the now-defunct social media app Parler that the Proud Boys were planning to "turn out in record numbers on Jan 6" and called its members "the most notorious group of extraordinary gentlemen".
Founded in 2016 by Canadian-British right-wing activist Gavin McInnes, the Proud Boys is a far-right, anti-immigrant, all male group with a history of street violence against left-wing groups. Tarrio became a national leader in 2018.
On Sunday, members of the group were reportedly involved in a violent demonstration in Portland, Oregon, that ended with a gunfight. Nobody was reported injured during the incident.
He was instructed to report to jail on 6 September.