The head of the US Capitol Police tried to reassure Americans on Wednesday that his force had addressed the security failings that culminated in the January 6 attack on Congress, while the nation's attorney general vowed that authorities would hold "all" perpetrators to account.
On the eve of the anniversary of the riot, Chief Thomas Manger said his officers would never be caught unprepared again, following the attack by thousands of former president Donald Trump's supporters trying to stop the certification of Joe Biden's presidential victory.
The police force that guards the US Capitol was so woefully unprepared for what happened that they could not even access vital riot gear because someone had left it locked on a bus.
“No more locked buses where they can’t access it,” Democratic Senator Amy Klobuchar told Chief Manger at a hearing. “That was an unbelievable story, just horrific. They're looking at the equipment and they can't get it.”
The chief responded that would “not happen again".
He went on to say he was confident the Capitol police are now a “stronger, better-prepared” force and outlined reforms his department has taken following the attack, including improving intelligence-gathering capabilities.
It has also created a critical-incident response plan to prevent delays in receiving help from other forces — a problem that became glaringly obvious on January 6, when it took several hours for the National Guard to provide backup.
US Attorney General Merrick Garland meanwhile said at the Justice Department that authorities would not rest until all those responsible for last year's attack are held to account.
“We will follow the facts wherever they lead,” Mr Garland said in a speech. “The actions we have taken thus far will not be our last.”
The investigation into the attack is the largest in the Justice Department’s history. So far, at least 725 people have been arrested and 350 others are still being sought by the FBI, including 250 of whom are accused of assaulting police officers.
Prosecutors remain “committed to holding all January 6 perpetrators, at any level, accountable under law," he said.
Mr Garland also detailed the serious assaults on law enforcement officers, describing in detail how officers were beaten and shocked with stun guns.
During January’s riot, one officer was beaten and shocked with a stun gun repeatedly until he had a heart attack; another was foaming at the mouth and screaming for help as rioters crushed him between two doors and bashed him in the head with his own weapon.
“Those involved must be held accountable, and there is no higher priority for us at the Department of Justice,” Mr Garland said.
More than 140 prosecutors from the District of Columbia and other offices across the country are taking part in the probe. Investigators have poured through more than 20,000 hours of video footage and issued more than 5,000 subpoenas. Mr Garland commended the public for providing more than 300,000 tips to help officials track down those responsible.
However, despite hundreds of criminal probes into the unrest and the reform of the Capitol Police, President Joe Biden will speak on the anniversary knowing that much of the country still celebrates the insurrection.
Underlining the political divisions, senior Republicans appear set to skip commemorations organised by the Democratic-led Congress on Thursday, including Mr Biden's speech inside Statuary Hall.
Mr Trump himself continues to push the unfounded claim, which at least two major news agencies now simply refer to as a "lie", that the 2020 election was stolen by Mr Biden — a conspiracy theory debunked through multiple court findings and vote recounts.
He had been planning to hold a press conference in Florida on Thursday, but abruptly abandoned the plan in a statement Tuesday that reiterated claims that the 2020 election was a “crime.”
“[Mr Biden will] speak to the historical significance of January 6, what it means for the country one year later,” White House Press Secretary Jen Psaki said.
In his remarks to the Senate committee, Chief Manger spoke of his badly prepared officers who had to face down angry Trump supporters pouring over police barricades, smashing windows and vandalising property.
Despite improvements to its tactics, the Capitol Police force is still reeling, with Chief Manger saying the department is significantly understaffed.
Agencies contributed to this report.