Donald Trump is facing federal criminal charges over the mishandling of classified documents at his Florida estate.
However, given the legal battles ahead it may take months or even years before a jury is asked to return a verdict or a plea deal is reached.
The former US president has branded the investigation a “witch hunt” and says it is a “dark day” for the US.
Here is what you need to know about the process and what to expect on the way.
What is an indictment?
An indictment is a written statement of charges against a person filed by a grand jury, a group of up to 23 people who consider whether there is probable cause the individual committed a crime.
What is the case about?
The federal indictment follows an investigation by special counsel Jack Smith into whether Trump broke the law by holding onto hundreds of documents, including some marked top-secret, at his Palm Beach property Mar-a-Lago and whether he sought to obstruct the government’s efforts to recover the records.
Trump has insisted he was entitled to keep the classified documents when he left the White House and has claimed – without evidence – that he had declassified them.
It is one of many ongoing investigations involving Trump, who has already been indicted in New York on 34 counts of falsifying business records.
Why was a special counsel involved?
Mr Smith’s appointment was a recognition by US Attorney General Merrick Garland of the politics involved in an investigation into a former president and current White House candidate.
Mr Garland himself was selected by President Biden, whom Mr Trump is seeking to challenge for the White House in 2024.
Special counsels are appointed in cases in which the Justice Department perceives itself as having a conflict or where it is deemed to be in the public interest to have someone outside the government come in and take responsibility for a matter.
What are the charges?
The actual indictment against Trump remains sealed but the federal grand jury has reportedly charged him with seven criminal counts, including obstruction of justice.
According to NBC News, one of the charges against Trump is under the Espionage Act.
Will Trump be arrested?
The 76-year-old has revealed he has been summoned to self-report to court in Miami at 3pm on Tuesday, meaning he will not be arrested.
Trump is already under constant US Secret Service protection.
What will happen next in court?
Trump will be brought before a federal judge and may be asked to enter a plea when the charges are put to him at a formal arraignment.
A judge will set release conditions after hearing from both prosecutors and the defence.
This could see Trump, through his lawyers, commit to attend future proceedings, not break any laws, and to abide by possible travel restrictions or notification requirements.
In the coming weeks, the two sides are set to discuss the timeline for the government to turn over evidence to Trump’s team in a process known as discovery and the handling of classified material in the case.
The defence will also prepare any pretrial motions, such as to throw out charges or exclude evidence.
Analysis: This case will rock the US
Will Trump be held in jail?
Factors a judge assesses in considering whether to detain someone before trial include a defendant’s flight risk, danger to the community, and violent criminal record.
Will he be fingerprinted?
Federal criminal defendants must be processed before or after appearing in court and this includes the collection of fingerprints.
However, it is unclear if he will be required to give a DNA sample.
Does a federal indictment prevent Trump running for office?
No, neither the indictment nor a conviction would prevent Trump from running for or winning the presidency in 2024.
The New York case also demonstrated that criminal charges have actually boosted his fundraising.
The campaign announced it raised more than $4m (£3.2m) in the 24 hours after that indictment became public, beating its previous record after the FBI search of Trump’s Mar-a-Lago property.
Could a trial happen before the 2024 election?
That is a question that will depend largely on the federal judge dealing with the case.
Trump’s legal team will probably want to delay a trial until after the election, and prosecutors might want to push for the case to be resolved well before the winner of the Republican presidential nomination is decided next summer.