• Seven U.S. Capitol Police officers filed a lawsuit accusing former President Donald Trump and others of being directly responsible for the deadly invasion of the Capitol on Jan. 6.
• The officers allege the defendants conspired to stop Congress from confirming President Joe Biden's Electoral College victory "through the use of force, intimidation, and threats."
• The lawsuit, filed in Washington federal district court, lists as defendants more than two dozen people and entities, including Republican operative Roger Stone and the far-right Proud Boys.

Seven U.S. Capitol Police officers filed a federal lawsuit Thursday accusing former President Donald Trump, far-right "violent extremist groups" and others of being directly responsible for the deadly invasion of the Capitol on Jan. 6.

The lawsuit was filed against more than two dozen people and entities, including Republican operative Roger Stone and the far-right Proud Boys group. It alleges the defendants conspired to stop Congress from confirming President Joe Biden's Electoral College victory "through the use of force, intimidation, and threats."

Their actions violated the Ku Klux Klan Act, which is intended to protect against political violence and intimidation, and other laws, the lawsuit alleges.

"Defendants' unlawful efforts culminated in the January 6 mass attack on the United States Capitol and the brutal, physical assault of hundreds of law enforcement officers," says the officers' legal complaint.

"Many Defendants in this case planned, aided, and actively participated in that attack. All Defendants are responsible for it," according to the lawsuit.

The complaint says the seven officers were "violently assaulted, spat on, tear-gassed, bear-sprayed, subjected to racial slurs and epithets, and put in fear for their lives" as they defended the Capitol from a mob of Trump supporters.

Their legal action marks at least the fourth lawsuit against Trump related to the Capitol riot and the second to be filed by members of the Capitol Police force.

In February, the NAACP and House Homeland Security Chairman Bennie Thompson, D-Miss., sued Trump, his former personal lawyer Rudy Giuliani, the Proud Boys and the Oath Keepers, another extremist group, alleging they conspired to incite the riot.

The next month, Rep. Eric Swalwell, D-Calif., filed his own lawsuit against Trump and Giuliani, as well as Rep. Mo Brooks, R-Ala., accusing them of being "wholly responsible" for the mob's destruction. All three men spoke to crowds of Trump's supporters at the "Stop the Steal" rally outside the White House on Jan. 6, when Congress at the nearby Capitol was set to convene to confirm Biden's victory.

In late March, Capitol Police officers Sidney Hemby and James Blassingame filed a lawsuit blaming Trump for the injuries they suffered, and continue to suffer from, due to the invasion. They are each seeking more than $75,000 in compensatory damages.

"As this lawsuit makes clear, the Jan. 6 insurrection was not just an attack on individuals, but an attack on democracy itself," said Damon Hewitt, president and executive director of the Lawyers' Committee for Civil Rights Under Law, which is representing the officers in the case filed Thursday.

"It was a blatant attempt to stifle the votes and voices of millions of Americans, particularly Black voters," Hewitt said in a press release.

The officers in a joint statement said their jobs have become "infinitely more dangerous" after Jan. 6.

"We want to do what we can to make sure the people who did this are held accountable and that no one can do this again," they said in the statement.

Trump was impeached in the Democrat-led House in January on a charge of inciting the riot, with 10 Republicans supporting the measure. He was acquitted in the Senate, where a two-thirds vote was required for conviction.

But questions about Trump's role in the attempted insurrection have hardly faded in the wake of his acquittal.

House Speaker Nancy Pelosi, D-Calif., formed a select committee to investigate the attack after Senate Republicans shot down an attempt to form an equally bipartisan, "9/11-style" commission. Trump could be called to testify as part of that probe, House Majority Whip James Clyburn, D-S.C., said last month.

On Wednesday, the select committee issued expansive requests for records from numerous federal agencies, as well as the Trump White House, as part of their review.

Meanwhile, a Capitol Police officer who shot and killed rioter Ashli Babbitt as she attempted to break into the Speaker's Lobby was cleared by the USCP after an internal probe.

The officer, whose identity has not been officially disclosed, will reveal himself for the first time in a televised interview set to air Thursday evening on NBC Nightly News with Lester Holt.