Bennie G. Thompson, a Democrat who represents Mississippi’s 2nd Congressional District in the U.S. House, is chairman of the House Select Committee to Investigate the January 6th Attack on the United States Capitol and chairman of the House Homeland Security Committee.

On Jan. 6, a violent mob attacked the citadel of our democracy — the U.S. Capitol — in an attempt to prevent Congress from doing its constitutional duty to certify the results of the 2020 presidential election.

On Tuesday, the bipartisan Select Committee on the January 6th Attack on the United States Capitol begins its work investigating the facts, circumstances and causes of this assault on our democracy.

I had hoped that such an investigation would be carried out by an independent commission composed of national security experts, like the panel created by Congress after the terrorist attacks of Sept. 11, 2001. However, once the House Republican leadership rejected — and Senate Minority Leader Mitch McConnell filibustered — bipartisan legislation to establish such a commission, we in the House believed we had no choice but to establish a select committee. In a recent poll, 72 percent of Americans agree there is more we must learn about that day.

Many of the Jan. 6 rioters have stated in their court pleadings that they stormed the Capitol believing they were acting on behalf of, or even at the behest of, then-President Donald Trump. The protection of our democracy demands that we comprehensively investigate what drove Americans to riot and violently assault Capitol Police, Metropolitan Police and other law enforcement officers to access the inner sanctum of Congress and private offices of top congressional leaders, including the speaker of the House.

Jan. 6 was supposed to be about the peaceful transfer of power after an election, a hallmark of democracy and our American tradition. The rioters went to the Capitol that day to obstruct this solemn action — and nearly succeeded while defacing and looting the halls of the Capitol in the process. The committee will provide the definitive accounting of one of the darkest days in our history. Armed with answers, we hope to identify actions that Congress and the executive branch can take to help ensure that it never happens again.

The bipartisan members of the committee believe strongly it is important to begin our work by hearing from law enforcement officers who defended the Capitol on Jan. 6. On Tuesday, we will be joined by Capitol Police officers Aquilino Gonell and Harry Dunn and Metropolitan Police officers Daniel Hodges and Michael Fanone. These officers will provide firsthand accounts of the chaos of that day and the violence perpetrated by the rioters.

Fanone voluntarily rushed to the Capitol with his partner when he heard about the attacks. As a result of his bravery that day, he suffered a traumatic brain injury and a heart attack. In a video that has now been shared widely, Hodges can be seen being crushed by the mob as he and his fellow officers sought to defend a narrow hallway leading to a Capitol entrance. Dunn was one of the first officers to speak publicly about what law enforcement encountered when the rioters stormed the Capitol and the racial epithets he and others faced. Gonell, a veteran who had been deployed to Iraq, defended the Capitol against rioters who hurled chants of “traitor.” While pulling an officer who had fallen to the ground away from the rioters, Gonell was beaten with a pole carrying an American flag.

The officers’ testimony will bring into focus individual acts of heroism by law enforcement that day. The officers will also speak to how, more than six months after the attack, law enforcement officers continue to deal with the physical, mental and emotional effects of that day. This conversation is an important step, as we look to bolster protection of the Capitol and our democracy.

Regrettably, some are already focusing their energies on maligning the select committee before its work has even begun. We will not be distracted by politically motivated sideshows.

This hearing is just the beginning of the select committee’s work; when it comes to the security of the Capitol — and our democracy — nothing will be off-limits. We will do what is necessary to understand what happened, why and how. And we will make recommendations to help ensure it never happens again. We owe it to the country we love to provide the answers that the American people deserve.