A former organizer of the far-right Proud Boys extremist group was sentenced on Thursday to 17 years in prison for spearheading an attack on the U.S. Capitol to prevent the peaceful transfer of power from Donald Trump to Joe Biden after the 2020 presidential election.

The sentence for Joseph Biggs is the second longest among hundreds of Capitol riot cases so far, after the 18-year prison sentence for Oath Keepers founder Stewart Rhodes.

Federal prosecutors had recommended a 33-year prison sentence for Biggs, who helped lead dozens of Proud Boys members and associates in marching to the U.S. Capitol on Jan. 6, 2021. Biggs and other Proud Boys joined the mob that broke through police lines and forced lawmakers to flee, disrupting the joint session of Congress for certifying the electoral victory by Biden, a Democrat.

“I know that I messed up that day,” Biggs told the judge just before being sentenced, “but I’m not a terrorist.”

The judge who sentenced Biggs also will separately sentence four other Proud Boys who were convicted by a jury in May after a four-month trial in Washington, D.C., that laid bare far-right extremists’ embrace of lies by Trump, a Republican, that the 2020 election was stolen from him.

Enrique Tarrio, a Miami resident who was the Proud Boys’ national chairman and top leader, is scheduled to be sentenced on Tuesday. His sentencing was moved from Wednesday to next week because U.S. District Judge Timothy Kelly was sick.Tarrio wasn’t in Washington on Jan. 6. He had been arrested two days before the Capitol riot on charges that he defaced a Black Lives Matter banner during an earlier rally in the nation’s capital, and he complied with a judge’s order to leave the city after his arrest. He picked Biggs and Proud Boys chapter president Ethan Nordean to be the group’s leaders on the ground in his absence, prosecutors said.

Biggs, of Ormond Beach, Florida, was a self-described Proud Boys organizer. He served in the U.S. Army for eight years before getting medically discharged in 2013. Biggs later worked as a correspondent for Infowars, the website operated by conspiracy theorist Alex Jones.

Biggs, Tarrio, Nordean and Proud Boys chapter leader Zachary Rehl were convicted of charges including seditious conspiracy, a rarely brought Civil War-era offense. A fifth Proud Boys member, Dominic Pezzola, was acquitted of seditious conspiracy but was convicted of other serious charges.

Prosecutors also recommended prison sentences of 33 years for Tarrio, 30 years for Rehl, 27 years for Nordean and 20 years for Pezzola. The judge is scheduled to sentence Rehl later on Thursday. Pezzola and Nordean are scheduled to be sentenced on Friday.

Defense attorneys argued that the Justice Department was unfairly holding their clients responsible for the violent actions of others in the crowd of Trump supporters at the Capitol.