While the committee has no legal powers to prosecute Mr Trump, it could choose to refer criminal charges to the US government's chief lawyer, Attorney General Merrick Garland.

In a recent court case over the release of emails by his lawyer, there were hints the committee could do just that.

The Democratic judge said it was "likely" Mr Trump had committed the crimes alleged by the committee.

Those crimes include obstructing the vote count in Congress, and conspiring to defraud the US by overturning the election results, which can both be punishable by fines or jail terms.

An interim report of the committee's findings, due this June, may pile the pressure on the attorney general to act.

Still, proving the crimes alleged by the committee would be difficult and politically controversial. No former president has ever been prosecuted.

Even if a conviction was secured, "it would likely be overturned absent some new evidence showing an active role in planning or facilitating the riot", says criminal defence lawyer Jonathan Turley, who was called by Republicans to testify at Trump's impeachment hearings.

The greatest danger, he said, could come from Mr Trump's response to the investigation if, for example, evidence was destroyed or false statements were made.

"Those are often the most common tripwires in Washington scandals, but we have not seen such allegations against Trump thus far," Mr Turley said.

A few days before the storming of Congress, the top election official in the state of Georgia received an unusual phone call.

"I just want to find 11,780 votes," an agitated Mr Trump told Georgia's Republican Secretary of State, Brad Raffensperger.

The votes would have given Mr Trump victory in the key 2020 swing state. Alleging unsubstantiated electoral fraud, Mr Trump suggested such an outcome might be possible if Mr Raffensperger could "re-examine" the result.

The 11,780 votes never materialised. "We believe our numbers are right," Mr Raffensperger said.

The chief prosecutor of Georgia's Fulton County, Fani Willis, launched an investigation into potential state election crimes, punishable by fines or imprisonment.

Mr Trump views the case as a "witch hunt", but his call to Mr Raffensperger could be an "incriminating statement", said Barbara McQuade, a professor of law at the University of Michigan.

Prosecutors would need to prove beyond reasonable doubt that Mr Trump knew his actions were fraudulent, though.

Judges have granted a request to open a special grand jury to see whether there is evidence of this. Grand juries are groups of citizens given legal powers to gather evidence and testimony.

But so far, "there has been little evidence offered beyond the call itself", Professor Turley said.

Mr Turley believes Mr Trump's "greatest threat has always been tax and bank fraud allegations in New York".

For over two years since 2019, Manhattan District Attorney Cyrus Vance and his team had pored over Mr Trump's finances in search of possible crimes.

Those alleged crimes included inflating the value of assets to obtain loans, a type of fraud which can carry prison sentences.

For prosecutors, getting their hands on Mr Trump's tax returns, and charging his company's chief financial officer with tax fraud, were two major breakthroughs.

Then in late 2021, Mr Vance left office and was replaced by fellow Democrat Alvin Bragg.

To take the case forward, the two prosecutors leading the investigation, Carey Dunne and Mark Pomerantz, tried to convince their new boss they had enough evidence to bring criminal charges.

He disagreed, the prosecutors resigned and the investigation was paused.

Their team had "no doubt about whether [Mr Trump] committed crimes - he did," Mr Pomerantz wrote in his resignation letter to Mr Bragg.

Those alleged crimes have been strenuously denied by Mr Trump.

If Mr Bragg does ever bring charges, he really must get it right because "the justice system would be on display", says Daniel R Alonso, a former New York state prosecutor.

To complicate matters, some of the allegations from the Vance probe are being looked at by New York's attorney general in a separate civil investigation, which opened in 2019. This week, a judge held Mr Trump in contempt for failing to turn over files to investigators.

"She's not my type," Mr Trump said in response to allegations he sexually assaulted a columnist in the 1990s. "It never happened, OK?"

That was back in 2019, days after E Jean Carroll made the allegations. She subsequently sued Mr Trump for calling her a liar.

The case is currently stuck in legal quicksand. Mr Trump counter-sued, and last month a judge blocked the case, saying it seemed that the former president appeared to be a play to delay Ms Carroll's legal actions.

The former president is also attempting a unique legal move. Instead of being sued as a private individual, he is arguing that it is not he, but the US government, who should be the defendant in the case.

Under national law, US government employees can be granted immunity from defamation claims like Ms Carroll's.

In theory, Mr Trump could be granted such immunity if the courts decide he spoke about Ms Carroll's allegations in his official capacity as president.

"It's a legal issue that is unprecedented," Professor McQuade said.

When Mr Trump left the White House, he took boxes of records with him to his Mar-a-Lago resort in Florida.

Under the Presidential Records Act, removing official records may constitute a criminal offence.

Keeping records enables presidents to be held accountable for their actions in office, says presidential historian Lindsay Chervinsky. But enforcing the Presidential Records act is "complicated", she says, because the law requires the "goodwill" of presidents to preserve their records.

What does that mean for the records at Mar-a-Lago, then?

According to the Washington Post, the US Justice Department has taken steps towards investigating Mr Trump's removal of those records, which were retrieved by the government in January.

Some of the boxes were marked as "classified", the newspaper reported.

Mr Trump claims the government "did not 'find' anything", and that Democrats were merely "in search of their next scam".

Mr Trump's records dispute is "uncharted territory" says Ms Chervinsky.

But it's unlikely the former president could be in real trouble over the Records Act, says Mr Turley. The law "is a bit of a paper tiger and presidents have routinely run afoul of its provisions", he says.

Not quite. A long list of other investigations and potential lawsuits includes:

• The Washington DC attorney general's criminal investigation into the 6 January attack. Last year he said Mr Trump could possibly be charged for encouraging the violence but no action has been taken

• A lawsuit by the same DC attorney general, who has accused Mr Trump of misusing funds for his 2017 inauguration. The trial is expected to begin later this year

• Various lawsuits by police officers who have accused Mr Trump of inciting the 6 January attack in which they suffered injuries

• A lawsuit by Mr Trump's niece, Mary Trump, who says her uncle and his siblings allegedly cheated her out of inheritance. Trump has sought to dismiss the lawsuit, which was filed in a state court in New York City

• A lawsuit filed in Manhattan federal court by Mr Trump's former personal lawyer Michael Cohen, who alleges his old boss sent him back to prison in retaliation for writing a tell-all memoir