Former President Donald Trump has been indicted in the special counsel’s classified documents probe, sources familiar with the matter tells CNN. (Drew Angerer/Getty Images)

(CNN) — Former President Donald Trump has been indicted in the special counsel’s classified documents probe, sources familiar with the matter tell CNN, a stunning development that marks the first time a former president has faced federal charges.

Trump has been charged with seven counts in the indictment, according to another source familiar with the matter.

At least one of the charges against Trump will be a conspiracy charge, a source said.

The special counsel has been investigating Trump’s handling of classified documents that were brought to his Mar-a-Lago Florida resort after he left the White House in 2021, as well as possible obstruction of the investigation and government efforts to retrieve the material.

The former president wrote on Truth Social that he had been informed by the Justice Department he was indicted and that he was “summoned to appear at the Federal Courthouse in Miami on Tuesday, at 3 PM.”

“The corrupt Biden Administration has informed my attorneys that I have been Indicted, seemingly over the Boxes Hoax,” Trump wrote.

The special counsel declined to comment. The Justice Department is moving additional resources to Miami ahead of the expected appearance, according to a law enforcement source.

The federal indictment is the second time that Trump has been charged criminally this year. In April, the Manhattan district attorney charged Trump with 34 counts of falsifying business.

But the indictment from the special counsel marks a new and more perilous legal phase for a former president, who is running for president again in 2024 while facing criminal charges in two jurisdictions – and with two additional investigations into his conduct still underway.

The charges against Trump come just seven months since Attorney General Merrick Garland appointed Jack Smith as a special counsel after Trump announced he was running for president, in order to keep the investigation independent from the Biden Justice Department.

Now Trump will face federal charges from the special counsel at the same time that he is trying to unseat President Joe Biden in next year’s presidential election.

The White House declined to comment Thursday evening.

‘I am an innocent man’

Trump has railed against the special counsel investigation and the other probes into his conduct, claiming they are all efforts to stop him politically. The former president has insisted that any criminal charges will not stop his 2024 campaign.

Trump released a four-minute video Thursday evening repeating many of his past claims, including that the Justice Department is being weaponized and that the investigations into him are “election interference.”

“I am an innocent man. I did nothing wrong,” Trump said in the video.

Trump has long avoided legal culpability in his personal, professional and political lives. He has settled a number of private civil lawsuits through the years and paid his way out of disputes concerning the Trump Organization. As president, he was twice impeached by the Democratic-led House, but avoided conviction by the Senate.

But after leaving office, the Justice Department criminal investigations into the retention of classified information at Trump’s Mar-a-Lago resort and his efforts to overturn the 2020 election cast dark clouds over Trump. Smith’s investigation into January 6 and efforts to overturn the election is still ongoing.

And in addition to the Manhattan district attorney’s April indictment, Fulton County District Attorney Fani Willis is expected to announce in August whether there are any charges in her investigation into attempts to overturn the 2020 election in Georgia.

Trump’s allies rally to his defense

Trump’s congressional allies quickly rallied to his defense on social media, just as they did when Trump was indicted in New York in April.

“Sad day for America. God Bless President Trump,” tweeted House Judiciary Chairman Jim Jordan, an Ohio Republican.

“The radical Far Left will stop at nothing to interfere with the 2024 election in order to prop up the catastrophic presidency and desperate campaign of Joe Biden,” House GOP conference chairwoman Elise Stefanik, a New York Republican, said in a statement.

Sen. Josh Hawley, a Missouri Republican, tweeted, “If people in power can jail their political opponents at will, we don’t have a republic.”

Several Democrats who investigated Trump during his presidency, however, said that Thursday’s indictment showed no one was above the rule of law.

“Trump’s apparent indictment on multiple charges arising from his retention of classified materials is another affirmation of the rule of law. For four years, he acted like he was above the law. But he should be treated like any other lawbreaker. And today, he has been,” wrote Rep. Adam Schiff, the California Democrat who led the House’s first impeachment of Trump in 2019.

Classified documents found at Mar-a-Lago

The Justice Department’s investigation into Trump’s actions related to documents from his time in office burst into public view in August when FBI agents executed a search warrant at Mar-a-Lago and seized thousands of documents, including about 100 marked as classified. The FBI also subpoenaed the Trump Organization for surveillance video from the resort.

Prosecutors had said in court filings they were pursuing possible criminal mishandling of national security information and obstruction of justice. The DOJ previously alleged that the classified documents were “likely concealed and removed” from a storage room at Mar-a-Lago as part of an effort to “obstruct” the FBI’s investigation into Trump’s potential mishandling of classified materials.

After Trump returned 15 boxes of materials to the National Archives in January, the Justice Department subpoenaed Trump in May, seeking documents with classification markings that were still at Mar-a-Lago.

According to a lawsuit he later filed, Trump directed his staff to search for any remaining classified material to comply with the subpoena. After federal investigators retrieved documents from the resort in June, his lawyers later told investigators that they had searched the storage area and that all classified documents were accounted for.

Prosecutors said in August that that some documents were likely removed from a storage room before Trump’s lawyers examined the area, while they were trying to comply with the subpoena.

In recent months, prosecutors heard from dozens of witnesses, including Trump aides and employees of Mar-a-Lago and the Trump Organization. The bulk of the witnesses appeared before a grand jury in Washington, DC, but in recent weeks multiple witnesses testified before a grand jury in southern Florida.

Prosecutors obtained an audio tape of Trump talking about a classified Pentagon document during a 2021 Bedminster, New Jersey, meeting. On the recording, which was first reported by CNN, Trump acknowledged that the document was still classified, undercutting his argument that everything he brought with him to Mar-a-Lago had been declassified.