A recently retired Delaware County firefighter accused of lobbing a fire extinguisher at police and a father-and-son duo from Delaware caught on camera smashing windows and parading a Confederate flag through the Capitol surrendered to federal authorities Thursday to face charges tied to the Jan. 6 insurrectionist riot in Washington.

Prosecutors said Robert Sanford, a 26-year veteran of the Chester Fire Department who left the force in February, injured three people when he tossed the extinguisher at the head of an officer as part of a mob that broke through barricades on the Capitol’s west side. They noted that the incident was separate from a similar attack on Capital Police Officer Brian Sicknick.

Meanwhile, Kevin Seefried, 51, of Laurel, and his son Hunter had already allegedly breached the building through a window they helped smash open. While the younger Seefried took selfies, authorities said, his father marched through the building’s corridors, waving the Confederate flag that, he would later tell FBI agents, is usually posted outside his home.

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All three men — like the dozens of others charged so far with participating in the melee stirred up by President Donald Trump — were identified from the more than 126,000 photographs and videos uploaded to the internet by other rioters or submitted as tips in the days after the attack.

Sanford and the Seefrieds have each confessed, authorities said, but all maintain they did not go to Washington as part of any organized group intent on starting trouble.

“He obviously was caught up in a bad moment,” said Sanford’s attorney, Enrique Latoison, noting that his client had never been arrested before. “That maybe minute of his life that he’s been accused of does not outweigh 55 years of a clean track record he’s been displaying.”

Still, U.S. Magistrate Judge Henry S. Perkin ordered him detained without bail until he could be transferred to Washington, where his case will play out.

“He’s not charged with simply taking a free bus ride to D.C.,” the judge said, adding that the riot Sanford allegedly participated in “was a danger to our democracy and our legislators.”

According to the charging documents in his case, Sanford was turned in by a close friend he had confided in after his photo — showing him with a grizzled gray goatee and a knit cap bearing the initials “CFD” — began circulating among social media sleuths seeking to identify the brawlers involved in the scene outside the Capitol.

Up until that point, investigators had been pursuing tips that those initials stood for the Chicago Fire Department and had been investigating another firefighter in that city that tipsters had incorrectly identified as the man in the photo.

The image had been extracted from a video that showed the suspect hurling a fire extinguisher at the helmeted head of an officer who was trying to restrain other rioters. It ricocheted off the officer’s helmet and struck one of his colleagues before bouncing again and hitting a third officer as the man who threw it fled the scene.

The tip from Sanford’s friend led investigators to refocus their search to Delaware County, according to the court filings. He told authorities that Sanford had traveled that day to Washington on a free bus organized by other pro-Trump supporters and then marched to the Capitol “following the president’s instructions.”

Though Sanford confessed to breaching Capitol grounds, court filings say, he did not tell his friend anything about throwing a fire extinguisher at police.

The Seefrieds, too, were turned in by a confidant. One of Hunter Seefried’s coworkers alerted the FBI after he allegedly bragged about breaching the Capitol at work, investigators said.

Agents later identified him and his father as part of a crowd that smashed through a Capitol window with a 2x4 and then clambered through to the inside. Both, investigators said, were part of a crowd that confronted Capitol police officers for 15 minutes early on during the assault.

When investigators tracked them down earlier this week at their rural house situated near a chicken coop close to Delaware’s border with Maryland — they explained that they initially traveled to Washington to hear Trump speak, according to court filings.

Both men were charged with entering a restricted area and disrupting Capitol proceedings and could be sentenced to up to 10 years in prison on the most serious count they face. They were released on GPS monitoring after a court hearing Thursday in Wilmington and ordered to report for court in Washington on Jan. 25.

Sanford, who faces three felony counts for allegedly assaulting officers, could be sentenced to as many as 20 years in prison on the most serious charge.

Contacted at home Thursday, his wife declined to comment.

Edward Reilly Jr., the head of the Chester firefighters union, issued a brief statement saying he “unequivocally condemns these acts of violence.”

Chester Mayor Thaddeus Kirkland said he hoped the legal system would “work according to its purpose” and bring Sanford to justice. He urged anyone with any information on other city employees or residents participating in the attack to contact authorities.

The Justice Department and the FBI continue a nationwide hunt for other riot participants that has led to charges against more than 70 people and the identification of 170 suspects so far.

Read Sanford’s charging documents:

Read the Seefrieds’ charging documents: