A former leader of the far-right Proud Boys extremist group was sentenced on Tuesday to more than three years behind bars for joining a plot to attack the U.S. Capitol nearly three years ago.

Charles Donohoe was the second Proud Boy to plead guilty to conspiring with other group members to obstruct the Jan. 6, 2021, joint session of Congress for certifying President Joe Biden’s electoral victory. His sentence could be a bellwether for other Proud Boys conspirators who agreed to cooperate with federal prosecutors.

Donohoe, 35, of Kernersville, North Carolina, apologized to his family, the law-enforcement officers who guarded the Capitol on Jan. 6 and “America as a whole” for his actions on Jan. 6.

“I knew what I was doing was illegal from the very moment those barricades got knocked down,” he said.