The House select committee investigating the Jan 6, 2021, attack on the Capitol voted Monday to send to the Justice Department for possible prosecution a recommendation that former President Donald Trump be charged with four crimes related to his attempt to overturn the presidential election.

The four criminal referrals include obstruction of an official proceeding, conspiracy to defraud the US, conspiracy to make false statements, and incitement of an insurrection.

The move has no legal weight but marks the first time in US history that Congress has made such a referral for a former president.

Key findings in the committee's 18-month investigation include allegations that Trump disseminated false allegations of fraud related to the 2020 election, provoking his supporters to violence on Jan 6, according to the executive summary, which the committee released following the Monday meeting.

"We understand the gravity of each and every referral we are making today just as we understand the magnitude of the crime against democracy that we describe in our report, but we have gone where the facts and the law lead us and inescapably, they lead us here," said Maryland Democratic Representative Jamie Raskin.

The panel referred five other Trump allies: Mark Meadows, Trump's final chief of staff; lawyers Rudolph Giuliani, John Eastman, Jeffrey Clark, and Kenneth Chesebro, for potential prosecution for actions the committee said warranted Justice Department investigation. The charges could carry lengthy prison sentences if federal prosecutors choose to pursue them.

During Monday's meeting, the committee played new video footage of an October interview with Hope Hicks, a longtime adviser to Trump, who described unsuccessful efforts to have him tone down his rhetoric about the election.

In a video clip, she said after the election she became increasingly concerned that Trump's falsehoods about the election were damaging his legacy. "Nobody will care about my legacy if I lose," Trump had told Hicks. "So, that won't matter. The only thing that matters is winning."

The committee also presented messages exchanged between Hicks and Hogan Gidley, another adviser to Trump, while the Jan 6 attack was occurring.

"Hey. I know you're seeing this. But he really should tweet something about Being NON-violent," Gidley said in a message.

"I'm not there," Hicks responded. "I suggested it several times Monday and Tuesday and he refused."

Chairman Bennie Thompson, Democrat of Mississippi, said the criminal justice system can provide accountability. "We have every confidence that the work of this committee will help provide a roadmap to justice," Thompson said.

The committee also voted 9-0 to approve its final report, which will include findings, interview transcripts, and legislative recommendations. The full report is expected to be released Wednesday.

The committee, which will be dissolved on Jan 3 with the new Republican controlled House, has conducted more than 1,000 interviews, held 10 public hearings, and collected more than a million documents since it launched in July 2021.

The committee is also referring four House members to the Ethics Committee for ignoring the panel's subpoenas.

Committee members have agreed to make all evidence and transcripts of depositions publicly available. Chairman Bennie G. Thompson (D-Miss.) said most "non-sensitive" materials would be released by end of 2022.