Washington DC - Speaking before today's one-year anniversary of the attack on the US Capitol, Attorney General Merrick Garland pledged Wednesday to hold to account those involved "at any level" in the riot, whether they were present during the chaos or not.

In his speech at the Justice Department billed as an update for employees on the insurrection investigation, Garland pushed back against critics who have questioned his commitment to aggressively target those who may have organized or incited the riot.

He called the inquiry the "largest, most complex, and most resource-intensive" in the department’s history and noted that such probes take time. "We will follow the facts – not an agenda or an assumption," he said. "The facts tell us where to go next."

Noting that 145 rioters have pleaded guilty to misdemeanors and another 20 have pleaded guilty to felonies, the attorney general said prosecutors have issued more than 5,000 subpoenas, and investigators have seized about 2,000 electronic devices, pored through 20,000 hours of video footage and evaluated 300,000 tips from the public.

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"We understand that there are questions about how long the investigation will take, and about what exactly we are doing," he said.

"Our answer is, and will continue to be, the same answer we would give with respect to any ongoing investigation: as long as it takes and whatever it takes for justice to be done – consistent with the facts and the law."

Garland did not mention former President Donald Trump by name or provide any hints about whom might be in prosecutors’ crosshairs beyond the 725 people already charged in the violent assault by a mob seeking to block Congress’ certification of President Joe Biden’s victory.

Garland’s speech came as the department has faced criticism this week over whether it has aggressively pursued those who played roles in planning or inciting the riot.

Representative Ruben Gallego, a Democrat from Arizona, accused Garland of being "extremely weak" and "feckless" in how his department has pursued the probe.

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"There should be a lot more of the organizers of January 6 that should be arrested by now," Gallego told CNN on Tuesday.

Sandra Garza, the longtime girlfriend of Capitol Police Officer Brian Sicknick, who died a day after battling rioters, said Trump "needs to be in prison."

"I hold Donald Trump 100% responsible for what happened on January 6 and all of the people that have enabled him, enabled him that day, and continue to enable him now." Garza told PBS NewsHour on Monday.

Brian Sicknick was sprayed with a chemical substance during the insurrection and collapsed hours later. He died the next night at a local hospital. Though a medical examiner determined he had suffered two strokes and died of natural causes, the Capitol Police consider his death to have been in the line of duty.

More than 100 police officers were injured during a clash with thousands of Trump supporters, many of whom had attended a rally where the president urged them to head to the Capitol and "fight like hell."

Authorities said the violence contributed to five deaths, including Sicknick’s.

Garland called for a moment of silence during his speech for Sicknick and four other officers who committed suicide in the weeks after the attack.

In his speech, the attorney general said the Justice Department had also stepped up its enforcement of the rise in violence targeting "those who serve the public," including election workers, journalists, flight crews, and local elected officials. Capitol Police have also recorded a sharp spike in threats against members of Congress and senators.

"We have all seen that Americans who serve and interact with the public at every level – many of whom make our democracy work every day – have been unlawfully targeted with threats of violence and actual violence," Garland said.

The threats "are permeating so many parts of our national life that they risk becoming normalized and routine if we do not stop them," he warned.