“This cannot happen again,” she said. “This was a very scary moment for America and it cannot set a precedent that the way you deal with political opposition is through violence and destruction.”

The Department of Justice has aggressively gone after demonstrators who caused violence during the protests over police brutality,charging more than 300 with crimes including civil disorder and burglary. In many cases,prosecutors pushed to keep them locked up while they await trial despite the virus crisis that has ravaged jails and prisons across the US.

Then-Deputy Attorney General Jeffrey Rosen,who stepped into the top job when Barr resigned last month,told prosecutors in a memo in September that they should consider the use of seditious conspiracy charges against violent demonstrators,saying it does not require proof of a plot to overthrow the US government. No one charged in the civil unrest sparked by George Floyd’s death has actually been charged with sedition.

The charge,which carries up to 20 years in prison,could apply to those who “by force prevent,hinder or delay the execution” of any U.S. law or “by force seize,take,or possess any property of the United States contrary to the authority thereof,” Rosen wrote.

He cited as a hypothetical example:"a group has conspired to take a federal courthouse or other federal property by force.”

“I do think there are some pretty strong cases,or at least some potential cases,under that statute,” Levenson said of those at the Capitol on Wednesday.

The mob smashed windows and broke doors,sending lawmakers into hiding as they began Electoral College votes affirming Democrat Joe Biden’s victory. Some rioters,many of whom weren't wearing masks,were captured in videos and photos posted all over social media.

“It’s always helpful to prosecutors if people pose for pictures in the midst of committing crimes,” said Stanford Law School professor David Sklansky,a former federal prosecutor in California.

The violence happened hours after Trump called on his supporters to “fight” to stop the “steal” of the election and march on the Capitol,while Trump’s personal lawyer,Rudy Giuliani,called for “trial by combat”.

Trump’s speech at the rally before the chaos broke out likely would not be considered illegally inciting violence because he didn’t specifically call for people to storm the Capitol,Sklansky said.

First Amendment freedoms mean speech has to be calculated to produce imminent violence to be considered criminal,he said. Similarly,comments by Giuliani,even those about “trial by combat,” were likely also not specific enough to be considered possibly criminal.

Four people died in Wednesday’s chaos,including a woman who was shot and killed by police inside the Capitol. Three other people died after “medical emergencies” related to the breach. More than 50 Capitol and DC police were injured,including several who were hospitalised,officials said.

AP