A Democratic lawmaker filed a lawsuit on Tuesday accusing former President Donald Trump and lawyer Rudy Giuliani of conspiring to incite the violent riot that shook the U.S. Capitol on Jan. 6.

The lawsuit by Representative Bennie Thompson, a Democrat who chairs the House of Representatives Homeland Security Committee, in U.S. District Court in Washington.

The U.S. Senate acquitted Trump of inciting the riot at the Capitol. The Senate vote of 57-43 fell short of the two-thirds majority needed to convict Trump on a charge of incitement of insurrection after a five-day impeachment trial but he can still be sued.

“The insurrection was the result of a carefully orchestrated plan by Trump, Giuliani and extremist groups like the Oath Keepers and Proud Boys, all of whom shared a common goal of employing intimidation, harassment and threats to stop the certification of the Electoral College,” according to a press release announcing the lawsuit.

The National Association for the Advancement of Colored People and attorneys from the law firm Cohen Milstein Sellers & Toll PLLC are handling the litigation.

Other members of Congress, including Democratic Representatives Hank Johnson and Bonnie Watson Coleman, are also expected to join the lawsuit,

More than 18 people associated with the Proud Boys have been charged so far for their alleged role during the riots, and three alleged associates of the Oath Keepers have been indicted on charges they conspired to storm the U.S. Capitol as far back as November.