A government watchdog group has filed a criminal complaint calling for an immediate investigation into Donald Trump by the FBI and Department of Justice to determine whether or not the US president is guilty of sedition.
The complaint was filed by the Citizens for Responsibility and Ethics (CREW) in Washington and focuses on the attack on the US Capitol on 6 January.
CREW's complaint suggests the attack was made to disrupt the transfer of power between Mr Trump and the president-elect, Joe Biden, by stopping Congress from counting the states' electoral votes.
It also claims Mr Trump directly incited the riot that took place.
CREW's executive director, Noah Bookbinder, posted a statement to the group's website demanding Mr Trump answer for his part in the attack.
"In what will be remembered as a dark day for American democracy, President Trump and his co-conspirators appear to have engaged in nothing less than an attempt to overthrow the government by force," Mr Bookbinder said. "This cannot go unanswered."
The complaint includes references to Mr Trump's words immediately preceding the attack.
Mr Trump is quoted as telling his supporters they were going to "stop the steal" and that they needed to "fight much harder" because they would "never take back our country with weakness." He told rally-goers that "you have to show strength, and you have to be strong."
"Trump's supporters did exactly what he urged them to do," CREW wrote in its complaint.
According to CREW, the combination of Mr Trump's instructions and the actual attack on the US Capitol amount to evidence of sedition.
"While President Trump and his associates likely comitted a multitude of federal criminal offenses prior to and during the insurrectionary events of 6 January, 2021, the president's larger purpose appears to have been the violent overthrow of the United States government by delaying, hindering or stopping Congress from affirming the results of the 2020 presidential election," the complaint said.
CREW said a sedition accusation should be reserved only for the "most extreme circumstances," before claiming the attack on the Capitol "is such a circumstance."
"It appears that President Trump engaged in a seditious conspiracy to prevent, hinder, or delay by force the lawful transfer of power and to thus overthrow the government of the United States," it said.
At the same time CREW filed its complaint, the US House of Representatives convened and impeached Mr Trump for a second time, making him the first US president ever to be impeached twice.
The Senate majority leader, Mitch McConnell, refused to call the Senate into emergency session in order to hold a hearing for Mr Trump.
As a result, the president will not be convicted until sometime after Mr Biden's inauguration.