Whodunnit? He did it.

Donald Trump – businessman, celebrity president, golfer and digital trading card star – is also a likely criminal, the congressional panel investigating the January 6 attack on the US Capitol concluded on Monday.

The committee’s referral of Trump to the justice department on multiple potential charges could not be described as a surprise after a year and half of work that spanned 10 public hearings, more than a thousand interviews, millions of documents and some recent leaks to the media.

Yet take a step back and consider how it will look to future historians. A former president of the United States stands accused by Congress of obstructing an official proceeding, conspiring to defraud the United States, conspiring to make a false statement and inciting, assisting or aiding or comforting an insurrection.

“We understand the gravity of each and every referral we are making today just as we understand the magnitude of the crime against democracy that we describe in our report,” said congressman Jamie Raskin with flinty authority, as if pronouncing a verdict in a hushed courtroom. “But we have gone where the facts and the law lead us, and inescapably they lead us here.”

The committee’s work has often earned comparisons to a television thriller or true crime podcast with help from producer James Goldston, the former president of ABC News. On Monday, at a meeting that lasted about 70 minutes, it served up its denouement and did not disappoint. Along with the style, there was serious substance.

Just as before, congressional aides, journalists and members of the public gathered in a caucus room measuring 74ft long by 54ft feet wide with six windows, two crystal chandeliers hanging from a double-height ceiling decorated with classical motifs. It once was the site of some of the most publicised hearings of the House Un-American Activities Committee in the 1950s.

It was also recently renamed the Speaker Nancy Pelosi caucus room – exquisitely fitting since it was the House speaker, not Trump, who acted in a presidential manner on January 6, seeking to rally security forces and keep democracy running even as the actual president tried to burn it all down.

Bennie Thompson, the bald, bespectacled, white-bearded chairman, hammered the now familiar gavel for the last time. He spoke of a country that remains “in strange and uncharted waters” and warned that, if America is to survive as a nation of laws and democracy, “this can never happen again”.

He handed over to vice-chairwoman Liz Cheney, who unexpectedly emerged as many liberals’ favorite conservative during the hearings, given her unyielding denunciations of Trump and his allies. She paid the ultimate price by losing her congressional seat to a pro-Trump Republican in Wyoming.

On Monday, she did little to quell suspicions that she has a presidential run in her future by speaking of her great-great grandfather’s service during the civil war and quoting Ronald Reagan. As for Trump’s conduct around January 6, Cheney was scathing: “No man who would behave that way at that moment in time can ever serve in any position of authority in our nation again. He is unfit for any office.”

The panel of seven Democrats and five Republicans served up a helpful montage of video clips that functioned as a reminder of both Trump’s malfeasance and its own excellent work over the past 18 months. It began with scenes of chaos outside the Capitol and testimony from Capitol police officer Caroline Edwards: “There were officers on the ground; they were bleeding. They were throwing up … I saw friends with blood all over their faces. I was slipping in people’s blood.”

It also gave a summing up of points so pithy that they could be written on the back of a digital trading card: Trump knew he lost; Trump pressured state officials to overturn the election; Trump pressured vice-president Pence to overturn the election (once again chants of “Hang Mike Pence!” filled the room); Trump summoned the mob; 187 minutes. Dereliction of duty.

The film ended with Trump’s pathetic statement to a camera on 7 January: “I don’t want to say the election’s over.”

Individual members of the committee then took turns to present a different facet of the evidence. Congressman Adam Schiff, another emerging star, showed a striking image of real electoral certificates juxtaposed with the fake ones that Trump and his allies hoped to deploy instead. He described the treatment of Georgia election worker Ruby Freeman and others as “callous, inhuman, inexcusable and dangerous – and those responsible should be held accountable”.

There was also some new evidence, including a recent interview with longtime Trump aide Hope Hicks.

She testified that both she and Eric Herschmann, a former White House lawyer, had urged Trump to tell his supporters to be peaceful before the Capitol riot but “he refused”.

Describing a conversation she had with Trump, she said he told her that no one would care about his legacy if he lost the election. Hicks told the committee that Trump told her: “The only thing that matters is winning.”

Appropriately, it fell to Raskin to “bring it home”. The Maryland congressman had emerged as a clarion voice of moral clarity as he led a second senate impeachment trial of Trump. He continued to show a penetrating intelligence and an ardent faith in the constitution during the committee hearings.

When he spoke forcefully on Monday, outlining the referrals of Trump to the justice department on criminal charges, the atmosphere in the room shifted to a more sombre one. The referrals are mostly symbolic with the department ultimately deciding whether to prosecute Trump or others.

But they provide another wake-up call for the Republican party. Since the last January 6 hearing, Trump has announced that he is running for the White House again while his handpicked election-denying candidates have been routed in the midterm elections. The ghosts of elections past, present and future are converging. There has seldom been a better opportunity for Republicans to disown him.

The committee, which will dissolve on 3 January with the new Republican-controlled House, voted to approve its final report, expected later this week. Thompson brought down the gavel and people in the public gallery broke into polite but heartfelt applause. After a year and a half wading through obstruction, hype and scepticism, the chairman and his team delivered the goods.