WASHINGTON >> Rioters locked up for their roles in the Jan. 6 Capitol attack were released while judges began dismissing dozens of pending cases Tuesday after President Donald Trump’s sweeping grant of clemency to all 1,500-plus people charged in the insurrection that shook the foundation of American democracy.

With the stroke of a pen on his first day back in the White House, Trump’s order upended the largest prosecution in Justice Department history, freeing from prison people caught on camera viciously attacking police as well as leaders of far-right extremist groups convicted of orchestrating violent plots to stop the peaceful transfer of power after his 2020 election loss.

The federal Bureau of Prisons by Tuesday morning had released all of the more than 200 people in its custody for Jan. 6 crimes, officials told The Associated Press.

The pardons and commutations cement Trump’s efforts to downplay the violence that left more than 100 police officers injured as the mob fueled by his lies about the 2020 election stormed the Capitol and halted the certification of President Joe Biden’s victory.

Trump’s decision to grant clemency to even rioters who assaulted police — whom his own vice president recently said “obviously” shouldn’t be pardoned — underscores how Trump has returned to power emboldened to take actions once believed politically unthinkable. And it shows how Trump plans to radically overhaul the Justice Department that also brought criminal charges against him in two cases he contends were politically motivated.

Trump defended the pardons Tuesday, saying the defendants had “already served years in prison” in conditions the president described as “disgusting” and “inhumane.”

The former leaders of the Oath Keepers and Proud Boys, who were convicted of seditious conspiracy in the most serious cases brought by the Justice Department, were both released from prison hours after Trump signed the clemency order. Stewart Rhodes, of Granbury, Texas, was serving an 18-year prison sentence, and Enrique Tarrio, of Miami, was serving a 22-year sentence.

The federal courthouse in Washington, which has been jammed with Jan. 6 cases over the last four years, was quiet Tuesday as proceedings were abruptly canceled. Hallways that would have been teeming with prospective jurors were empty. Judges who would have been hearing cases were not on the bench.

Those pardoned include more than 250 people who were convicted of assault charges, some having attacked police with makeshift weapons such as flagpoles, a hockey stick and a crutch. Many of the attacks were captured on surveillance or body camera footage that showed rioters engaging in hand-to-hand combat with police as officers desperately fought to beat back the angry crowd.

One man was sentenced to seven years in prison for trying to smash a widow with a metal tomahawk and hurling makeshift weapons at police officers guarding the building. Another man received 20 years behind bars for swinging poles at officers defending a tunnel, striking an officer in the head with a metal crutch and attacking police with pepper spray and broken pieces of furniture.

At least four officers who were at the Capitol later died by suicide. Capitol Police officer Brian Sicknick collapsed and died after engaging with the protesters. A medical examiner later determined he died of natural causes.