Authorities on Thursday arrested a Colorado Springs man who allegedly was among a group of rioters who “repeatedly engaged in violence against law enforcement officers guarding the (U.S.) Capitol” on Jan. 6, 2021, according to a news release from the Department of Justice.

Jonathan Grace, 49, is expected to make his first court appearance Thursday in Denver on charges that include felony civil disorder.

Grace is accused of joining a mob of rioters who were pushing back against a line of officers in the Lower West Terrace and tunnel areas of the Capitol, according to the release. At the end of the tunnel were two sets of doors that opened directly into the Capitol.

“GRACE made his way deep into the mob of rioters inside the tunnel, put his head down, and began using his body weight to push in unison with the rioters against police officers,” reads a statement from the investigating special agent whose name was redacted. “As GRACE and the rioters thrusted their collective body weight into the officers, one officer could be heard screaming in agonizing pain as he was smashed between a shield and a metal door frame.”

After officers temporarily cleared people from the tunnel, authorities say Grace watched as rioters dragged an officer from the tunnel and “brutally attacked him.” He then rejoined the rioters at the front of the tunnel as they once again pushed against police inside the tunnel.

Grace retreated once an officer sprayed chemical irritants.

His case is being prosecuted by the U.S. Attorney’s Office for the District of Columbia and the Department of Justice National Security Division’s Counterterrorism Section.

The FBI identified Grace using publicly available video footage, U.S. Capitol Police surveillance footage and body camera footage from officers. The FBI also reviewed Grace’s financial transactions, which indicated he traveled from Colorado to the Washington, D.C., area and back in the days surrounding Jan. 6.

Grace joins more than 1,000 others who have been arrested in connection with the Jan. 6 Capitol breach that disrupted Congress’ count of the electoral votes and certification of President Joe Biden. The investigation is ongoing.