The January 6th Committee concluded its work on Monday by referring criminal charges against former President Trump to the Department of Justice.

The committee’s recommendation seeks to hold Trump accountable for “a multi-part scheme” to overturn the 2020 presidential election and to thwart the peaceful transfer of power to President Joe Biden.

“The president has an affirmative and primary constitutional duty to act to take care that the laws be faithfully executed,” said Rep. Jamie Raskin at the hearing. “Nothing could be a greater betrayal of this duty than to assist in insurrection against the constitutional order.”

The referral caps 18 months of investigation and public hearings into the violent riot at the Capitol on Jan. 6, 2021, which temporarily halted the certification of Biden’s victory.

The committee voted 9-0 to approve referrals on four charges: obstruction of an official proceeding, conspiracy to defraud the United States, conspiracy to make a false statement and incitement of an insurrection.

The Department of Justice is under no obligation to act on the referral.

The committee also approved criminal referrals for five Trump allies, including his chief of staff, Mark Meadows, and attorney Rudy Giuliani, for their roles in the events leading to the Capitol riot.

In its final public hearing, the House select committee reiterated its findings, which it had spelled out in a series of hearings over the summer. Rep. Bennie Thompson, the committee chairman, said that Trump was the first president to refuse to accept the will of the voters.

“He lost the 2020 election and knew it,” Thompson said. “In the end, he summoned a mob to Washington, and knowing they were armed and angry, pointed them to the Capitol and told them to ‘fight like hell.’ There is no doubt about this.”

Thompson said that full accountability for those events “can only be found in the criminal justice system,” and that such accountability is needed to ensure that such an insurrection never happens again.

The committee will dissolve as Republicans take control of the House of Representatives in January. Trump announced in November that he will run for president again in 2024.