A NEW JERSEY gym owner has become the first person to plead guilty to assaulting a law enforcement officer during the riot at the US Capitol in Washington DC.

Scott Fairlamb’s deal with federal prosecutors could be a benchmark for dozens of other cases in which Capitol rioters clashed with police on 6 January.

Fairlamb’s lawyer said prosecutors will recommend a prison sentence ranging from about three to five years, but the judge is not bound by that term of the plea agreement.

His plea comes less than two weeks after a group of police officers testified at a congressional hearing about their harrowing confrontations with the mob of insurrectionists. Five officers who were at the Capitol that day have died, four killed themselves.

The Justice Department has said that rioters assaulted approximately 140 police officers. About 80 of them were US Capitol Police officers and about 60 were from the Washington DC Metropolitan Police Department.

Fairlamb, a former mixed martial arts fighter whose brother is a US Secret Service agent, was one of the very first rioters to breach the Capitol after other rioters smashed windows using riot shields and kicked out a locked door, according to federal prosecutors.

After leaving the building, Fairlamb harassed a line of police officers, shouting in their faces and blocking their progress through the mob, prosecutors wrote in a court filing.

A video showed him holding a collapsible baton and shouting, and shouting, “What (do) patriots do? We disarm them and then we storm the Capitol.”

US District Judge Royce Lamberth accepted the plea for Fairlamb, who has been jailed since his 22 January arrest at his home in Stockholm, New Jersey.

Fairlamb, 44, pleaded guilty to two counts, obstruction of an official proceeding and assaulting a Metropolitan Police Department officer. The counts carry a maximum of more than 20 years in prison.

He had been indicted on 12 counts, including civil disorder, assaulting a police officer and engaging in physical violence in a restricted building or grounds.