House Speaker Nancy Pelosi announced Monday the creation of an independent, 9/11 Commission-style investigation of the Jan. 6 riot at the U.S. Capitol in a letter to Democratic colleagues.

What You Need To Know

  • House Speaker Nancy Pelosi announced the creation of an independent, 9/11 Commission-style investigation of the Jan. 6 riot at the U.S. Capitol

  • The move comes just days after former President Donald J. Trump was acquitted by the Senate in his historic second impeachment trial, accused of "incitement of insurrection" for his role in the Capitol riot

  • Pelosi also announced additional spending to boost security at the U.S. Capitol

  • Lawmakers on both sides of the aisle called for an independent investigation into the deadly insurrection

"To protect our security, our security, our security, our next step will be to establish an outside, independent, 9/11-type commission to 'investigate and report on the facts and causes relating to the January 6, 2021, domestic terrorist attack upon the United States Capitol Complex … and relating to the interference with the peaceful transfer of power.'"

The National Commission on Terrorist Attacks, better known as the 9/11 Commission, was established to "to prepare a full and complete account of the circumstances surrounding the September 11, 2001 terrorist attacks, including preparedness for and the immediate response to the attacks." The commission was established on Nov. 27, 2002, released its findings on July 22, 2004, and dissolved that August.

Pelosi also announced additional spending to boost security at the U.S. Capitol; she had also previously asked retired Army Lt. Gen. Russel Honoré to lead an immediate review of the Capitol’s security process

“As we prepare for the Commission," Pelosi said, "it is also clear from General Honoré’s interim reporting that we must put forth a supplemental appropriation to provide for the safety of Members and the security of the Capitol."

On Tuesday, White House Press Secretary Jen Psaki said that though the commission was Congress' decision to make, President Joe Biden supports the investigation as well.

"He backs efforts to shed additional light on the facts to ensure something like that never happens again," Psaki said, adding: "We'll continue to work with Congress to identify measures that the federal government can take going forward to prevent violence we saw on Jan. 6th."

"There's a number of hearings that are upcoming in the coming weeks and we'll be cooperative with those of course," she noted.

The Senate announced its first hearings to examine the Jan. 6 siege of the Capitol, calling in the former chief of Capitol Police and the former heads of security for the House and Senate, all three of whom resigned immediately after the attack.

Two Senate committees will meet next week to begin a broad examination of the security failures that led to the vast breach, in which five people died. In addition to the Feb. 23 hearing, the two committees are pressing for information from almost two dozen agencies and departments about the response.

The Senate Homeland Security and Governmental Affairs Committee and the Senate Rules Committee announced Tuesday that they had invited former Capitol Police Chief Steven Sund, former Senate Sergeant at Arms Michael Stenger and former House Sergeant at Arms Paul Irving to the hearing, along with Robert Contee, the chief of the Metropolitan Police Department.

On Jan. 6, 2021, a mob of Trump supporters stormed the U.S. Capitol as the House, Senate, and Vice President were meeting to certify the electoral college results; 5 people were killed, including Capitol Police officer Brian D. Sicknick.

The move comes just days after former President Donald J. Trump, who spoke to supporters at a rally before the insurrection began, was acquitted by the Senate in his historic second impeachment trial on the charge of "incitement of insurrection" for his role in the riot.

"It is clear from his findings and from the impeachment trial that we must get to the truth of how this happened," Pelosi said.

Lawmakers on both sides of the aisle signaled a desire for further investigations into the deadly Jan. 6 riot.

"There should be a complete investigation about what happened. What was known, who knew it and when they knew, all that, because that builds the basis so this never happens again," Louisiana Sen. Bill Cassidy, one of the 7 Republicans who voted to convict Trump on Saturday, told ABC's "This Week with George Stephanopoulos."

"There’s still more evidence that the American people need and deserve to hear and a 9/11 commission is a way to make sure that we secure the Capitol going forward," Democratic Sen. Chris Coons of Delaware said." And that we lay bare the record of just how responsible and how abjectly violating of his constitutional oath President Trump really was."

"[Trump's] behavior after the election was over the top," staunch Trump ally Sen. Lindsey Graham (R-SC) said. "We need a 9/11 commission to find out what happened and make sure it never happens again."

House prosecutors laid out a case that he was an "inciter in chief" who unleashed a mob by stoking a monthslong campaign of spreading debunked conspiracy theories and false violent rhetoric that the 2020 election was stolen from him.

Trump’s lawyers countered that Trump’s words were not intended to incite the violence and that impeachment was nothing but a "witch hunt" designed to prevent him from serving in office again.

The conviction tally was the most bipartisan in American history but left Trump to declare victory and signal a political revival while a bitterly divided GOP bickered over its direction and his place in the party.

Senate Minority Leader McConnell told Republican senators shortly before the vote that he would vote to acquit Trump, but in a blistering speech after the vote, the Kentucky Republican said the president was "practically and morally responsible for provoking the events of that day."

However, McConnell said that the Senate's hands were tied to do anything about it because Trump was out of office. (The Senate held two separate votes on the constitutionality of the trial and upheld it both times.)

"It was powerful to hear the 57 guilties and then it was puzzling to hear and see Mitch McConnell stand and say ‘not guilty’ and then, minutes later, stand again and say he was guilty of everything,” Rep. Madeleine Dean (D-PA), one of the House impeachment managers, said on "This Week" Sunday. “History will remember that statement of speaking out of two sides of his mouth,” she said.

Dean also backed the idea of an impartial investigative commission "not guided by politics but filled with people who would stand up to the courage of their conviction."

Trump is the only president in U.S. history to be impeached twice.

The Associated Press contributed to this report.