Washington (AFP) - The footage was more violent, more eye-popping than any prime-time network crime show. And it was real.

Video images capturing the raging anger and violence of the mob ransacking the US Congress provided a vivid and visceral picture of the 2021 insurrection on Capitol Hill.

Dozens of journalists, politicians and congressional staffers crammed into the Capitol's stately Cannon Caucus Room Thursday for the first hearings into the January 6 committee's findings, their febrile chatter quickly turning to stunned silence as opening speeches were followed by video of the riot playing out on a huge screen.

A minute-by-minute visual breakdown -- much of it composed of new footage -- served as a painful reminder of the mayhem that played out as a mob attempted to disrupt the formal vote by lawmakers to transfer power from Donald Trump to Joe Biden. 

The committee showed the moment when the mob, spurred on by members of the neofascist Proud Boys, overwhelmed police at the perimeter of the Capitol complex, casting aside barricades as they surged forward.

Police officers were seen desperately trying -- and failing -- to keep the crowd at bay as rioters climbed scaffolding, hurled chairs and eventually breached the halls of Congress.

The public gallery sat rapt, watching graphic images of the clashes that could have spiraled into a much larger tragedy had lawmakers not been evacuated.

Some people in the public seats looked away at times but many held up phones to record the footage as hordes of rioters -- some in tactical gear -- were seen streaming into the Capitol through broken windows and other breached entry points. 

The video juxtaposed images of insurrectionists overrunning the complex from the outside with footage of the mob roaming the Capitol -- and video and audio of Trump whipping up the crowd beforehand and praising the mob afterwards. 

'Blood, sweat and tears'

US Capitol Police officer Caroline Edwards also gave an account of the violence, in which she was concussed when she cracked her head on the Capitol steps after being knocked over by the surging mob.

She spoke of her "literal blood, sweat and tears... shed that day defending the building that I spent countless holidays and weekends working in."

Measuring roughly the size of two tennis courts, its gilded walls adorned with Corinthian floor-to-ceiling pillars illuminated by crystal chandeliers, the airy, magisterial Cannon Caucus Room in an annex off the main Capitol building is designed to inspire awe. 

Just yards from the main Capitol building in downtown Washington, it was the venue for House Un-American Activities hearings in 1948 during the Soviet "reds under the bed" moral panic, and more recently hearings for Trump's first impeachment.

The former president -- still the nearest thing Republicans have to an official party leader -- wasn't present as lawmakers set out their case that he was to blame for the insurrection that left five dead in January 2021, just across the road.

Yet his presence was almost palpable on "opening night" for a what is certain to be a summer of blockbuster hearings.

Spectators had come to be part of history as the stiffly-named Select Committee to Investigate the January 6th Attack on the United States Capitol opened its case -- and history did not disappoint. 

The meticulously stage-managed made-for-TV session was the panel's first opportunity to show the public what they've learned from more than 1,000 witness interviews and 140,000 documents. 

Its central mission has been to assess the catalysts for the violence of a day unparalleled in history. 

But investigators were also tasked with assessing the extent of Trump's many suspect attempts to cling to power, and how they played into the bloodshed. 

There were excerpts of taped interviews with Trump administration and campaign officials who told members of Trump's inner circle there was no justification for overturning the election.

Trump's attorney general Bill Barr was shown telling investigators the defeated president's claims of fraud involving manipulated voting machines were "complete nonsense."

Trump's eldest daughter and former aide Ivanka Trump -- speaking for the first time about the fraud claims --  was shown saying she "accepted" Barr's rebuttal of the bogus allegations.

With no actual prosecutorial powers -- the Justice Department is pursuing a parallel criminal investigation -- the panel sees its job as convicting Trump in the court of public opinion. 

This may not be a heavy lift, as the question of Trump's criminality has already been settled in part, by a landmark ruling in March from a federal judge who said it was "more likely than not that President Trump corruptly attempted to obstruct the joint session of Congress on January 6."

"The illegality of the plan was obvious," he said.