BOSTON (AP) — A former Boston police officer was arrested Thursday on charges that he assaulted a police officer after storming the U.S. Capitol with the mob of President Donald Trump supporters on Jan. 6, 2021.

Joseph Robert Fisher is accused of pushing a chair into a Capitol police officer inside the building as the officer was running after another rioter who deployed pepper spray, according to court documents. Moments later, Fisher also “engaged in a physical assault” against the officer, which ended with Fisher on the ground, an FBI agent wrote in the court papers.

A current Boston police officer helped investigators identify Fisher in photographs, the agent wrote.

The 52-year-old was arrested at his home in Plymouth, Massachusetts and released on conditions after an initial court appearance Thursday. Fisher retired in 2016 after serving more than 20 years in the police force, including as part of the K-9 unit, a department spokesperson said.

He's charged with assaulting an officer, obstruction of law enforcement during a civil disorder and other crimes. The Associated Press sent an email to an attorney who represented Fisher for his initial appearance in Boston.

Fisher is among several people charged in the riot who were working or previously worked in law enforcement on Jan. 6. The rioter who received the longest sentence so far — 10 years in prison — was a

Also on Thursday, authorities arrested a Colorado man who prosecutors say was part of a group of rioters who violently pushed against officers desperately trying to defend the Capitol from the angry mob in a tunnel.

Jonathan Grace, of Colorado Springs, faces charges including felony civil disorder. The 49-year-old is also supposed to appear in court on Thursday in Denver. No attorney was immediately listed for him in court records.

Surveillance video shows Grace entering a tunnel where officers were lined up as they tried to beat back the mob. Grace can be seen putting his head down and using his body to push in unison with other rioters against the police line, authorities say. As the rioters pushed, one of officers screamed in pain while being crushed between a shield and a door frame in , according to court documents.

After officers at one point managed to clear rioters out of the tunnel, Grace watched as other rioters dragged a D.C. police officer out of the tunnel and brutally attacked him, authorities say. He then re-joined the rioters pushing against the police line and retreated only after officers sprayed a chemical irritant at the crowd, according to court documents.

that halted the certification of President Joe Biden’s victory and left dozens of police officers injured. All of the cases are being prosecuted in Washington D.C.’s federal court and authorities continue to make new arrests practically every week.

More than 540 defendants have pleaded guilty. Dozens more have been convicted by judges or juries after trials. More than 440 have been sentenced, with over half getting terms of imprisonment ranging from seven days to 10 years.

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Associated Press writer Michael Kunzelman contributed to this report.

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Follow the AP’s coverage of the Capitol riot at

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