Federal authorities said Tuesday they expect to soon charge hundreds of people in connection with the Capitol riot.
Officials added that they have directed a strike force to gather evidence for prosecutions for sedition and conspiracy.
And an FBI official confirmed a report that the FBI received intelligence regarding the possibility of violence in advance of Wednesday's riot, and shared that information with other law enforcement agencies in Washington.
"Yesterday, my office organized a strike force of prosecutors whose only orders are to build sedition charges related to most heinous acts that occurred in the Capitol, said Michael Sherwin, acting United States attorney for the District of Columbia, during a press conference. He noted that the maximum possible sentence for a person convicted of sedition is 20 years in prison.
Sherwin said more than 70 people so far have been arrested in connection with the riot last Wednesday by a mob of supporters of President Donald Trump, with another 100 or so criminal cases opened.
"That's the tip of the iceberg," said FBI Washington Field Office Assistant Director in Charge Steven D'Antuono
A number of those cases have involved relatively minor charges, but Sherwin said he expected charges to be upgraded for some people.
And he said he expects the number of people arrested "to geometrically increase" in coming weeks.
"We're going to focus on the most significant charges," Sherwin said. "This is only the beginning."
He said the "mind-blowing" array of charges being eyed by the FBI and Justice Department include felony murder, weapons possession, assault of police officer, civil rights violations, theft of mail, theft of computers and trespassing.
"For example, yesterday, we had grand jury in DC up," Sherwin said. "It was booked throughout entire day. We presented felony cases related to civil disorder, possession of weapons."
He said he had also tasked specific prosecutor in his office to focus on assaults on journalists during the riot.
"You will be found, you will be charged," Sherwin warned members of the mob, many of whom are believed to have returned to their homes around the country.
D'Antuono said that more than 100,000 digital files related to tips about the riot have been sent to investigators.
He also said "several individuals have" voluntarily disclosed their participation in the riot to authorities.
"Come forward," D'Antuono urged other participants.
He said that before the riot, the FBI "developed some intel that a number of individuals were planning to travel to DC with intention to cause violence."
"We shared that information and action was taken, as shown by arrest of Enrique Tarrio night before the rally. Other individuals were identified and travel disrupted," he said.
The riot left at least four people dead, among them a Capitol police officer. Two pipe bombs were found near the Capitol complex, by the headquarters of both the Republican National Committee and the Democratic National Committee.
The violence began after a Trump rally, where he, his son, and personal lawyer Rudy Giuliani urged a crowd to fight with him in his bid to get Congress to reject Joe Biden's election as president.