A man has been sentenced to 17 years in prison for his involvement in riots that shook Brazil's capital in January after the presidential election.
He was one of thousands who refused to accept the far-right president Jair Bolsonaro's loss, ransacking government buildings in protest.
Aecio Pereira, convicted of attempting a coup, is the first to be tried in connection with the attacks.
He denied wrongdoing and said he believed he was at a peaceful protest.
Pereira, 51, was arrested inside the Senate building, He had filmed himself at the Senate president's table during the riots, wearing a T-shirt marked with the words "Military Intervention" while he urged fellow supporters of Mr Bolsonaro to "take to the streets."
The mob he was part of claimed the election result was rigged and invaded the presidential palace and the high court in Brasilia, smashing windows, throwing furniture into fountains and vandalizing artwork.
Some had also been camping outside army buildings around the country calling for a military intervention.
"The [rioters'] objective was to violently seize Brasilia and spread a criminal attack against the rule of law across the country," Justice Cristiano Zanin said on Thursday as he sentenced Mr Pereira.
He is part of an initial group of four people that will be tried over the riots before Brazil's Supreme Court, which plans to hear 232 cases involving the most serious alleged crimes committed during the demonstrations.
Prosecutors are also investigating more than 1,000 others over the attacks, mostly on lesser charges.
Brazil's Supreme Court had also agreed to include Mr Bolsonaro in their riot probe, with prosecutors saying he may have incited a crime by questioning the legitimacy of October's presidential election.
Mr Bolsonaro was in Florida during the violence after refusing to take part in handing over the presidential sash to left-wing Luiz Inácio Lula da Silva.
Before narrowly losing last October's elections, he had publicly accused the Supreme Federal Court of being politically against him, and claimed the voting system was prone to fraud, despite no evidence to support those claims.
But Mr Bolsonaro denied encouraging the riots at time, saying they had gone beyond democratic protest.