(The Hill) – One of the Proud Boys leaders charged with conspiracy in connection to the Jan. 6, 2021, attack on the U.S. Capitol pleaded guilty on Friday, agreeing to cooperate with federal prosecutors as they prepare to tackle one of the biggest criminal cases stemming from last year’s breach.

Charles Donohoe, a 34-year-old leader of the right-wing group’s North Carolina chapter, pleaded guilty to one count of conspiracy to obstruct an official proceeding and one count of assaulting, resisting or impeding a law enforcement officer.

Donohoe was among a group of six Proud Boys leaders, including Enrique Tarrio, the organization’s national leader, charged with conspiracy last month.

He is the first member of the group to plead guilty and agree to cooperate with the government.

The conspiracy charge carries a maximum possible sentence of 20 years in prison. U.S. District Judge Timothy Kelly told Donohoe during a hearing Friday that federal sentencing guideline calculations would recommend a sentence in the range of 70 to 87 months in prison.

Tarrio entered an initial plea of not guilty earlier this week.

Prosecutors allege the group organized and rallied Proud Boys members to descend on D.C. with an aim to prevent or delay Congress from certifying President Biden’s 2020 electoral victory.

While Tarrio was not physically present at the Capitol on Jan. 6, having been arrested days before for destroying a Black Lives Matter banner that had been hung from a D.C. church, prosecutors say he led a Proud Boys conspiracy.

According to charging documents, Donohoe took on an increased role in coordinating with Proud Boys leaders in the days between Tarrio’s arrest and Jan. 6.

On Jan. 4, the day of Tarrio’s arrest, prosecutors say Donohoe started a new encrypted group chat with other Proud Boys leaders, saying in a message, “Hey have been instructed and listen to me real good! There is no planning of any sort. I need to be put into whatever new thing is created. Everything is compromised and we can be looking at Gang charges.”

Kelly recently vacated the court’s plan for trial in the case to begin on May 18 but has yet to set a new date.