Speaker Nancy Pelosi (D-Calif.) said Monday that a 9/11-style commission to investigate the Jan. 6 attack on the Capitol is the “next step” after the Senate impeachment trial concluded. 

The Speaker said in a "Dear Colleague" letter that the impeachment trial and Ret. Gen. Russel Honoré’s initial security review into how to prevent a similar incident make it “clear” that “we must get to the truth of how this happened.”

“To protect our security, our security, our security, our next step will be to establish an outside, independent 9/11-type Commission,” she said. 

The commission would “investigate and report on the facts and causes relating to the January 6, 2021 domestic terrorist attack upon the United States Capitol Complex" as well as "relating to the interference with the peaceful transfer of power, including facts and causes relating to the preparedness and response of the United States Capitol Police and other Federal, State, and local law enforcement in the National Capitol Region,” Pelosi said.

Requests for a commission similar to the one formed post-9/11 have picked up in the weeks since the breach at the Capitol led to the deaths of five people, including a Capitol Police officer, and scores of law enforcement injuries.  

Lawmakers who have called for such an investigation want to learn more about why law enforcement agencies were not more prepared to respond when supporters of former President Trump stormed the Capitol building, interrupting the counting of the Electoral College votes and forcing both chambers to recess and lawmakers to flee to secure locations. 

Several security leaders, including the Capitol Police chief, House sergeant-at-arms and Senate sergeant-at-arms, stepped down from their positions in the days afterward.

Pelosi, who served on a separate joint House and Senate committee looking into 9/11, previously said an independent commission to examine what happened Jan. 6 was all but inevitable. 

“We will have an after-action review; there will be a commission,” Pelosi said last month. 

Head Republicans on the House Administration, Homeland Security and Oversight and Reform committees — Reps. Rodney Davis (Ill.), John Katko (N.Y.), and James Comer (Ky.) — have proposed a bill that would create a bipartisan commission.

Some House Democrats are instead calling for a commission to focus generally on domestic terrorism and extremism, including how law enforcement responds to these perpetrators. 

Pelosi is looking to the “next step” after the Senate impeachment trial concluded this weekend with senators acquitting Trump after the House impeached him alleging that he incited the violence at the Capitol.

Seven Republican senators voted to convict the former president in the most bipartisan Senate impeachment trial vote, but the upper chamber did not reach the necessary two-thirds majority to convict Trump.