A Proud Boys member has pleaded guilty in connection with his participation in the fatal Capitol riot, with the terms of his plea deal adding that the New York man has also agreed to cooperate with the government.

Matthew Greene pleaded guilty to a pair of charges in the U.S. District Court for the District of Columbia on Wednesday. In the plea agreement, under which Greene pleaded guilty to conspiracy and obstruction of an official proceeding, the 34-year-old also agreed to cooperate with the Office of the U.S. Attorney for the District of Columbia.

The terms and conditions of that portion of the agreement include that Greene must cooperate “fully, truthfully, completely, and forthrightly” with the office, as well as other federal and/or state and local law enforcement entities. Such cooperation, per prosecutors, could include participation in “covert law enforcement activities.”

Per the Associated Press, Wednesday’s court development makes Greene the first Proud Boys member to have publicly pleaded guilty to conspiring with fellow members in an attempt to block Congress from certifying the 2020 vote. 

For the conspiracy count, a prison sentence could have been as high as five years, while the obstruction charge alone could have carried a sentence of up to 20 years. However, prosecutors—per CBS News—have already said they will likely recommend up to 51 months behind bars. Sentencing is set for next March.

The Jan. 6 attack followed Trump’s 2020 presidential election loss, with supporters of the former Apprentice host uniting behind fabrications regarding the vote. In recently released audio from an interview originally conducted in March, Trump was heard defending his supporters, some of whom participated in chants calling for violence against then-VP Mike Pence.