A retired Pennsylvania firefighter was arrested Thursday on federal charges that he threw a fire extinguisher that hit three Capitol Police officers during the violent siege on the Capitol last week.

Robert Sanford, 55, who retired last year from the Chester Fire Department, outside Philadelphia, turned himself in to the FBI to face charges that include assault of a police officer, disorderly conduct on Capitol grounds, civil disorder and unlawfully entering the Capitol.

Sanford, a supporter of President Donald Trump, got “caught up in the mob mentality,” his lawyer, Enrique Latoison, told The Associated Press.

The charges against Sanford are not related to the widely publicized attack on Officer Brian Sicknick, who also was assaulted with a fire extinguisher during the siege and who later died.

Sanford was held in Pennsylvania’s Lehigh County jail, where he had an initial court appearance by video Thursday.

Latoison argued to the judge that Sanford should be released on bail, citing his long service as a firefighter, his strong family ties and his lack of a criminal record. Sanford, a married father of three, did not go to Washington with weapons or the intent of rioting, and does not belong to any extremist groups, defense lawyer Enrique Latoison argued.

A federal prosecutor asserted that a search of Sanford’s house Thursday turned up a T-shirt associated with the Proud Boys, a far-right group. Latoison told AP afterward that an inventory of the search listed no such T-shirt, and he said Sanford vigorously denies owning one.

Noting the seriousness of the charges, the judge ordered Sanford to be held without bail, saying he presented a danger to the community.

Authorities said the case will be prosecuted in Washington.

The FBI asked the public this week to help identify a man seen in video stills who picked up a fire extinguisher and threw it at police outside the Capitol on Jan. 6. According to the charging documents, the extinguisher bounced off the heads of three officers, two of whom wore helmets.

Sanford, 55, traveled by bus with other people to the Capitol, according to documents. He told a friend when he returned home that he had been on the grounds for 10 minutes before leaving but did not mention throwing anything at officers, authorities said.

The friend saw the photos released by federal authorities and contacted police.