One of the suspects arrested in the violent Ferguson protest that left a police officer fighting for his life is a Missouri Democratic delegate and “extremely well-known” left-wing activist with a long history of clashes with law enforcement.

Keith Rose served as an alternate St. Louis delegate for the Democratic National Convention — due to start in Chicago on Monday — until he resigned over the weekend following an arrest for property damage Friday during demonstrations on the 10th anniversary of unarmed black teen Michael Brown’s shooting.

Rose, a longtime progressive activist, was also appointed this year to St. Louis’ Civilian Oversight Board, which is tasked with reviewing allegations of misconduct against the police department.

But Rose has a long history of conflict with law enforcement, including a 2014 arrest during the initial protests after Michael Brown’s killing by a white cop, and one in 2017 during another demonstration protesting the acquittal of a white officer in the shooting death of Anthony Lamar Smith, who was black.

Rose and three others sued the City of Ferguson for $20 million after his 2014 arrest over allegations of malicious prosecution, the Washington Post reported.

The activist was also part of a large class-action lawsuit filed against the City of St. Louis in 2017 alleging police mistreatment after the Smith protest, according to Fox 2 Now. The city settled and agreed to pay $4.91 million, or about $58,500 per person, to 84 protesters.

In both of those lawsuits, Rose and the plaintiffs alleged they were wrongfully detained in mass arrests or wrongfully prosecuted in the days following.

Another arrest comes from 2018 when he used a bike lock to chain his head to a revolving door at Missouri Sen. Roy Blunt’s office in protest of Supreme Court Justice Kavanaugh’s nomination, according to the St. Louis American.

Rose recused himself from Oversight Board duties this week after three St. Louis aldermen released a letter saying he was no longer able to “appear neutral and objective” on policing matters.

“I think any normal person would look at that and say ‘That there’s an issue,'” St. Louis Police Officers’ Association president Jay Schroeder told The Post of Rose’s position on the Police Oversight Board following his latest arrest at the Ferguson protest.

“When you have a civilian oversight board, you would want a fair and equal party when you look at these things — and I just don’t think he has the ability to look at things impartially.”

Rose’s lawyer, Javad Khazaeli, told The Post that his client stepped down from his oversight board duties so he is not a distraction — but he did not resign.

“He’s not going to resign because he did nothing wrong,” Khazaeli said.

Meanwhile, Schroder explained that Rose has been a regular face on the protest scene for at least ten years.

“He is extremely well known and involved,” Schroeder said, “He’s been the main agitating protester for almost a decade.”

Footage released by the Ferguson Police Department appeared to capture Rose rattling the gate protecting the building during the rowdy Friday demonstrations.

Some time later police moved to make arrests for the damage, and as demonstrators fled, one charged into Officer Travis Brown — slamming his head to the concrete and leaving him with a severe brain injury.

Rose has denied damaging the department’s fence and distanced himself from the alleged assault of Brown, telling 5 On Your Side through a lawyer that “violence is never acceptable” when exercising the right to peaceful assembly. He has not been charged in the officer’s assault.

Khazaeli rebuked the characterization of his client as an agitator and denied that he damaged any property.

“The Ferguson Police Department has released a video that shows our client did not break the fence — we’re confused as to why we’re still here,” the attorney said, adding that Rose was simply just “messing with it.”

“He’s an activist that has successfully sued the police department for violating constitutional rights when they’ve beaten him without justification. He’s never been convicted of anything. The one time he was charged, a judge found him not guilty. But he is a person who holds government accountable.”

Arresting documents accused Rose of kicking out a portion of the police department fence, causing over $750 in damage.

He is free on $500 bond.

Officer Brown remains in critical condition six days after he was hurt in the incident, which was captured on graphic footage Ferguson police released Tuesday.

His alleged attacker, 28-year-old Elijah Gannt, remains in jail on various assault charges.