Former US President Donald Trump has been criminally charged for the second time in three months.

This time, the subject is his handling of classified files after he left the White House. Thousands of documents were seized in an FBI search at his Florida estate Mar-a-Lago last year, including about 100 marked as classified.

Legal experts say that Mr Trump, who is running for president again in 2024, could face prison if convicted of mishandling the documents, or of obstructing the investigation into whether he did.

He has repeatedly denied any wrongdoing, and said he “never thought it possible that such a thing could happen to a former president of the United States”.

Here’s what to know, and what to expect next.

When will Trump be arrested?

On his social media platform Truth Social, Mr Trump said he has been asked to appear at a federal courthouse in Miami on Tuesday 13 June.

The US Secret Service will be meeting on Friday with the former president’s staff and the Secret Service officers assigned to him, a law enforcement official told the BBC’s US partner CBS News.

They will plan Trump’s travel to court in Florida, and his appearance to be arraigned.

Ahead of the hearing, US Secret Service agents will perform threat assessments of the federal courthouse in Miami and its surroundings, and work with court officers to form a security plan.

Will he be handcuffed and finger-printed?

Before news of the indictment broke, Carl Tobias, a law professor at the University of Richmond in Virginia, told the BBC that Mr Trump’s arrest would likely follow a similar pattern to his arrest in April on charges of falsifying business records in relation to alleged hush-money payments made to Stormy Daniels.

At the time, Mr Trump handed himself over to authorities in New York and appeared in court to plead not guilty. He was fingerprinted but he was not put in handcuffs and did not have a mugshot taken.

Mr Tobias said it was improbable that Mr Trump would be handcuffed or have his mugshot taken this time.

What Trump indictment actually means

“I think that is unlikely, given his stature as a former president and the slim likelihood that he’s a flight risk,” Mr Tobias said. “He’s going to show up to at least negotiate or fight… but I don’t think they need to use those types of procedures.”

Once Mr Trump’s arrest paperwork is completed, he will be considered under arrest and in custody. Once the paperwork is processed, he would be arraigned – meaning that he will hear the charges and enter a plea in court.

What is the case about?

When Mr Trump left office in January 2021, he was supposed to hand over all presidential records, which are considered federal property.

It is illegal for officials, including former presidents, to remove or keep classified documents at an unauthorised, insecure location.

But just months after Mr Trump left the White House, the US National Archives realised that some records were missing.

These included some of Mr Trump’s correspondence with North Korean leader Kim Jong-Un and a letter that former president Barack Obama left for Mr Trump when he left office.

The agency requested the records, and some were handed over.

In August 2022, the justice department searched Mr Trump’s Mar-a-Lago property, seizing a further 11,000 documents, some of which were marked as classified or top secret, and some which were marked “TS/SCI”, a designation for material that could cause “exceptionally grave” damage to US national security.

Other items included a binder of photos, a handwritten note, unspecified information about the president of France, and a clemency letter written on behalf of long-time Trump ally Roger Stone.

Could Mr Trump be jailed if convicted?

Prosecutors are yet to confirm what exact charges Mr Trump is facing. His lawyer Jim Trusty told CNN the former president had received details of the charges in a summons document.

He said they included conspiracy, false statements, obstruction of justice, and illegally retaining classified documents under the Espionage Act.

Several of these are considered serious charges.

Espionage Act violations can carry up to 10 years in prison, while obstruction of justice – also a felony – carries a maximum penalty of 20 years.

It is by no means certain that Mr Trump would be convicted. Some legal experts believe it would be difficult to prove that he committed a crime.

For the obstruction of justice charges, for example, the law notes that prosecutors would have to show that Mr Trump or members of his team “knowingly” mishandled materials “to impede, obstruct or influence” the investigation.

It may ultimately prove difficult to prove that Mr Trump knew what was happening. He could also feasibly argue that his staff mishandled the documents without his consent.

What has Trump said about the case?

Mr Trump announced his impending indictment on social media on Thursday night. The justice department has yet to comment.

In a series of Truth Social posts – as well as a video – Mr Trump repeatedly said he was innocent and characterised the indictment as “political warfare” against him before the 2024 election.

He has used a variety of arguments to defend his handling of the documents, including that he declassified the documents before they were discovered. While presidents have previously declassified documents directly, there is no evidence that Mr Trump did so or followed any existing procedure.

Mr Trump has also argued that some of the documents were personal and protected by executive privilege. This would mean that there was no requirement to turn them over to the national archives when he left office – the very premise of the case. The argument has largely been dismissed by legal experts.

David Super, a professor at Georgetown University Law Center, told the BBC that he believes Mr Trump’s lawyers are likely to argue that the former president was just a “really bad file clerk”.

A key aspect of the case could be an audio recording in which Mr Trump reportedly said he knowingly kept documents and acknowledged he was limited in his ability to declassify him.

If this were true, Mr Super said that “it pretty much sinks him because that shows that he knows the things he’s been saying in public are not true”.

How would charges affect Trump’s presidential campaign?

It is unclear what impact the new charges might have on Mr Trump’s popularity with his supporters.

His arrest in New York had negligible impact on his popularity, and he remained the clear frontrunner for the Republican presidential nomination for the 2024 general election.

From a legal standpoint, experts believe that the indictment – or even a possible conviction – does not present present an impediment to his bid to become president again.

Under US law, nothing prevents an individual from from running for office if facing criminal charges.

“It could certainly be a problem for him politically if he’s indicted, and certainly, if he’s convicted. People may think twice about whether they want to vote for him,” Mr Tobias said. “But I don’t think that will necessarily prevent his participation.”

At least two people have previously run for president with criminal convictions. In 1920, socialist candidate Eugene Debs ran for president despite having been convicted of the Espionage Act in connection with a 1918 anti-war speech.

Conspiracist Lyndon LaRouche also ran for the presidency on multiple occasions despite having been convicted of fraud in 1988. One of his presidential bids, in 1992, took place while he was at a federal prison in Minnesota.

Both lost the election. (BBC)

Update news