Of Donald Trump's many legal woes, the investigation into his alleged cover-up of a hush money payment to a porn star ahead of the 2016 presidential election could be the first to result in criminal charges.
If a Manhattan grand jury decides to indict him for his role in the scheme, the former president will be fingerprinted, photographed and potentially even handcuffed.
He'll also become the first US president, former or sitting, to be charged with a crime.
Over the weekend, Mr Trump, who is currently vying for the Republican presidential nomination in 2024, claimed on his social media site he expected to be arrested on Tuesday local time and called on his supporters to protest.
A lawyer for Mr Trump later clarified that the time line was "based on press reports".
The intense media speculation surrounding the possible indictment began with a New York Times article, published over a week ago.
The Times said the Manhattan District Attorney office's invitation to Mr Trump to testify before its grand jury signalled the longest-running investigation into the former president was likely coming to an end.
So far, no charges have been filed, but legal experts agree that could happen imminently.
Here's what we know so far.
The Stormy Daniels scandal
The investigation into the former president, overseen by Manhattan District Attorney Alvin Bragg, centres on a $US130,000 ($194,800) payment made by Donald Trump's then-lawyer Michael Cohen to adult film actor Stormy Daniels.
Ms Daniels, whose real name is Stephanie Clifford, revealed in 2018 she was paid by Cohen to hide an alleged sexual encounter with Mr Trump after meeting him at a golf tournament in 2006.
In 2011, Ms Daniels negotiated to sell the story to a celebrity magazine, which ultimately spiked it amid legal threats from Cohen, who was acting as Mr Trump's fixer.
Over the next five years, Ms Daniels made several failed bids to have the story published elsewhere.
But in October 2016, when the now infamous "Access Hollywood" tape, in which Mr Trump bragged about groping women, surfaced on the eve of the election, she saw another opportunity to come forward.
Cohen quickly sought to quash any renewed interest in Ms Daniels's story and the pair signed a deal for her silence.
To pay for it, Cohen used personal funds, which he transferred through a Delaware shell company.
Once in the White House, Mr Trump reimbursed his lawyer.
In 2018, Cohen pleaded guilty to several related charges in federal court, including federal campaign finance crimes tied to the hush money, and was sentenced to three years in prison.
He also publicly laid the blame on his boss, who denied both the affair and knowledge of the payout.
The district attorney's office then opened its own criminal investigation into the matter, looking beyond Cohen to Mr Trump.
What could Donald Trump be charged with?
The decision to file charges against Donald Trump lies with Alvin Bragg, a Democrat and the first black person elected to lead the Manhattan District Attorney's office, who the former president has accused of targeting him for political reasons.
Mr Bragg set up a grand jury to assess whether there was enough evidence — including witness testimony and corroborating text messages, emails and documents — to pursue a prosecution.
If he proceeds with one, legal experts say he may consider two potential charges, a misdemeanour and a felony.
The lesser charge relates to falsifying business documents, a New York State crime Mr Trump may have committed by claiming his payments to Cohen were for legal services.
That could be elevated to a felony charge if prosecutors can show Mr Trump intended to commit or conceal a second crime, likely a violation of election law, by arguing the hush money amounted to an improper campaign donation.
"No-one wants to be charged with felony, it's a serious crime," said Catherine Christian, a former financial prosecutor for the Manhattan district attorney.
"However, this particular charge, falsifying business records in the first degree, is the lowest level felony under New York State law."
Ms Christian said it would also be tricky for prosecutors to prove, though "not impossible", and any conviction would likely result in a fine or probation rather than jail time.
"It's definitely a felony, it can be proved. But practically many people have said, 'This is the felony you're getting him for?'"
When could an indictment happen?
Donald Trump's Truth Social prediction of his looming arrest was made without evidence, but legal experts say his indictment is likely to soon become a reality.
There are several signs the grand jury is wrapping up its work, including the offer extended to Mr Trump to appear before the panel, which he declined.
Robert Costello, a Trump ally and former legal adviser to Cohen, also testified on Monday, which some saw as a last-ditch attack on the prosecution's star witness.
"I think it's pretty likely at this point," said Sarah Krissoff, a former federal prosecutor in the US Attorney's Office for the Southern District of New York, now focused on white-collar and investigative cases.
"I would expect if it wasn't going to happen that we'd hear some very different messaging coming out of the district attorney's office, and they would dissuade us of this fact, but they haven't.
"So, I expect it's likely to come down shortly."
Once the grand jury has finished hearing from witnesses, the jurors — who meet on Monday, Wednesday and Thursday afternoons — will then vote on whether to file an indictment.
Ms Krissoff said the next step was for prosecutors to alert the legal counsel for the target, in this instance Mr Trump, to arrange a surrender, which constitutes an arrest.
He would then be arraigned, likely appearing in court in person later this week or early next week.
"That's what you would normally expect in these kind of circumstances," she said.
"This one obviously is a little exceptional given the parties involved."
Authorities in New York City and Washington, DC, are bracing for the possibility of unrest, with the New York Police Department and the US Secret Service coordinating to prevent any protests from escalating into violence.
"We are monitoring comments on social media, and the NYPD is doing their normal role of making sure there is no inappropriate actions in the city," New York City Mayor Eric Adams said Monday during a press conference.
"We are confident we're going to be able to do that."
So far there are no signs of major protests, though barricades have been erected around the Manhattan court complex.
And while a handful of pro- and anti-Trump demonstrators have gathered outside, they are far outnumbered by members of the media.
Where do the other Trump investigations stand?
Alongside the hush money case, there are several other high-profile investigations surrounding Donald Trump, including parallel criminal and civil probes into the Trump Organization's business dealings in New York City.
A special counsel was appointed to oversee two Department of Justice (DOJ) investigations into Mr Trump's alleged mishandling of classified documents and his role in the January 6 attack on the US Capitol in 2021.
But his efforts to subvert the outcome of the 2020 presidential election in Georgia, which are under investigation by Fulton County District Attorney Fani Willis, could prove the thorniest problem of all for the former president.
Ms Willis has said "decisions are imminent", with some observers floating the prospect she could use racketeering charges to indict multiple defendants for election-related crimes.
"Out of all of the pending legal issues that he has swirling in his world, this, if it ends up being about a pay-off to [Stormy] Daniels, is not going to be the most substantive crime that he's going to be facing as a charge," Ms Christian said.
"He has to worry about it, because it's a felony.
"But it's not going to be the one that I think is going to be keeping him and his attorneys up at night. The others are."
Ms Krissoff agreed, noting the public profiles of the prosecution's witnesses, including Ms Daniels and Cohen, could make them easy targets for the defence.
"Frankly, a lot of these witnesses that the district attorney's office is relying on are folks that have told their stories publicly, privately, in the press [and] numerous times to prosecutors before," she said.
"So, Trump's team is probably going to do some be able to do some damage and point out some inconsistencies in their statements."
Could an arrest end Trump's 2024 aspirations?
At present, Donald Trump remains the frontrunner to win the Republican nomination for president in 2024 — something he was quick to point out when raging over his potential arrest on Truth Social.
Ms Krissoff noted rusted-on Trump supporters were unlikely to be swayed by the underlying facts of the case, given they've been known to the public for years.
"This certainly is one for the history books," she said.
"[But] I expect that it will essentially roll off the backs of Trump supporters. I don't think they care."
As Ms Christian pointed out, there is also no specific clause in the US Constitution barring someone convicted of a felony from running for president, taking office, or even serving from behind bars.
Ultimately, none of the cases involving Mr Trump may even be resolved by the next election.
If Mr Trump were to be convicted of a crime while president, it would then be up to the US House and Senate to remove him from office.
And history has shown the twice-impeached president can hold onto power if his party controls Congress and is willing to back him.
"We're in wholly new territory here," Ms Christian said.
"This is something that has never happened."
