Donald Trump claims he will be arrested on Tuesday on charges stemming from an investigation into a $130,000 payment to porn star Stormy Daniels in 2016.
If he is, he would be the first former president to face criminal charges.
Here are some key questions on the issues at play in this case.
What is Trump accused of?
In 2016, adult film star Stormy Daniels contacted media outlets offering to sell her account of what she said was an adulterous affair she had with Donald Trump in 2006.
Mr Trump’s team got wind of this, and his lawyer Michael Cohen paid $130,000 to Ms Daniels to keep quiet.
This is not illegal. However, when Mr Trump reimbursed Mr Cohen, the record for the payment says it was for legal fees. Prosecutors say this amounts to Mr Trump falsifying business records, which is a misdemeanour – a criminal offence – in New York.
Prosecutors could also potentially allege that this breaks election law, because his attempt to hide his payments to Ms Daniels was motivated by not wanting voters to know he had an affair with her. Covering up a crime by falsifying records would be a felony, which is a more serious charge.
Even advocates for prosecution acknowledge that either way, this is by no means a clear-cut case. There is little precedent for such a prosecution, and past attempts to charge politicians with crossing the line between campaign finance and personal spending have ended in failure.
“It’s going to be tough,” says Catherine Christian, a former financial prosecutor for the New York City district attorney.
How the Trump-Stormy Daniels saga unfolded
Will he actually be charged?
The decision on whether to file charges rests with New York City District Attorney Alvin Bragg. He set up the grand jury to investigate whether there was enough evidence to pursue a prosecution, and he is the only one who knows if – or when – an indictment will be announced.
Last week, Mr Trump’s lawyers said that the former president was offered a chance to appear before the grand jury, which is considered a sign that the investigation is close to finishing.
The lawyers have downplayed suggestions that they or Mr Trump have any advance notice of an impending indictment, saying his comment about it being Tuesday were based on media reports.
However there are other signs that the grand jury is wrapping up. Both Michael Cohen and his former legal adviser Robert Costello – now a sharp critic – are expected to give testimony on Monday.
Mr Costello would be presented by Mr Trump’s defence team in an attempt to discredit Mr Cohen’s testimony.
What is a US grand jury?
What happens if Trump is arrested?
If he is charged, Mr Trump’s lawyers have indicated that the former president’s arrest would follow standard procedure.
That means he would travel from his home at Mar-a-Lago in Florida to make an appearance at the New York City courthouse, complete with a formal booking, fingerprints and mug shots.
Given the historic nature of such a move, and the security concerns involved, the way this would unfold is uncertain – and would likely be the subject of negotiation between the district attorney’s office and Mr Trump’s team.
Once the case is booked and a judge is selected, other details will fall into place, such as the timing of the trial and possible travel restrictions and bail requirements for the defendant.
A conviction on a misdemeanour would result in a fine. If Mr Trump were convicted on the felony charge, he would face a maximum sentence of four years in prison, although some legal experts predict a fine is more probable, and that any time behind bars is highly unlikely.
Will there be protests?
After suggesting in a social media post that he would be indicted on Tuesday, Mr Trump made repeated calls for mass protests from his supporters: “WE JUST CAN’T ALLOW THIS ANYMORE. THEY’RE KILLING OUR NATION AS WE SIT BACK & WATCH.”
His language echoes the angry rhetoric he employed prior to the attack on the US Capitol in 2021 and has raised concerns about the potential for violence.