Timeline from the above source:
Jan. 20: Trump leaves the White House. The Presidential Records Act requires that all documents be returned to the archives upon his departure.
May 6: Chief counsel for the National Archives emails Trump’s representatives, according to later reporting by the New York Times and the Washington Post. The Post quoted the email as reading, in part, “It is also our understanding that roughly two dozen boxes of original presidential records were kept in the Residence of the White House over the course of President Trump’s last year in office and have not been transferred to NARA, despite a determination by Pat Cipollone in the final days of the administration that they need to be.” Cipollone had been Trump’s White House counsel.
2022 Mid-January: The National Archives retrieves 15 boxes of records from Trump’s Mar-a-Lago home. The records were transported to the National Archives “following discussions with President Trump’s representatives in 2021,” the National Archives wrote in a press release it made available on its website on Feb. 7. “As required by the Presidential Records Act, these records should have been transferred to NARA from the White House at the end of the Trump administration in January 2021.”
Jan. 31: The National Archives issues a statement saying that some of the presidential records it received from Trump before he left office “had been torn up by former President Trump.”
Feb. 18: National archivist David Ferriero says in a letter to Congress that the agency had been communicating with Trump representatives about the return of documents throughout most of 2021. National Archives officials determined that those 15 boxes contained some classified information, so they contacted the Justice Department, Ferreiro’s letter said.
May 10: Acting archivist Debra Steidel Wall writes a letter to Trump attorney Evan Corcoran. In it, Wall denies a request from Corcoran to delay providing the FBI access to the 15 boxes that were retrieved. Wall writes that the National Archives had discovered in those boxes “over 100 documents with classified markings, comprising 700 pages.” (The National Archives made this letter public on its website on Aug. 23, a day after it was disclosed on Just the News, a conservative website run by Trump ally John Solomon.) (See the Aug. 26 entry: The FBI found 25 documents marked Top Secret.)
May 11: Trump accepts a grand jury subpoena addressed to the custodian of records for Trump, seeking documents marked as classified. Multiple news reports would later report this happened in the spring, citing unnamed sources. Trump’s attorneys confirmed the May 11 date in an Aug. 22 court filing.
May 16-18: FBI agents conduct a preliminary review of the 15 boxes that had been provided to the National Archives. They find classified documents in all but one box. They identify “184 unique documents bearing classification markings including 67 documents marked as confidential, 92 documents marked as secret, and 25 documents marked as top secret,” according to information later made public in the court’s Aug. 26 release of the Justice Department’s search warrant affidavit.
The boxes also include documents with markings for intelligence derived from monitoring foreign communications or from “clandestine human sources.” Documents with such classification markings typically contain national defense information.
Several of the documents also contain what appear to be Trump’s handwritten notes.
June 3: Justice Department officials travel to Mar-a-Lago, where they briefly meet with Trump, and retrieve more documents marked classified, according to The New York Times. A Trump lawyer signs a declaration indicating that all the materials marked classified were turned over, the Times and others reported. Trump’s attorneys later confirmed the June 3 visit and document retrieval.
At some point after the June 3 visit, investigators had learned that there could still be more classified documents at Mar-a-Lago, according to reporting in the New York Times and The Wall Street Journal that cited unnamed sources.
June 22: Trump is served with another subpoena, this time for surveillance footage from Mar-a-Lago. Trump’s attorneys would later acknowledge receipt of the June 22 subpoena, writing in a court filing: “At President Trump’s direction, service of that subpoena was voluntarily accepted, and responsive video footage was provided to the government.”
Aug. 8: The FBI, with a search warrant in hand, searches Mar-a-Lago, removing another 25 boxes of documents. According to a receipt released by the Justice Department, the documents include “various classified/TS/SCI documents.” TS/SCI stands for top-secret/sensitive compartmented information. There are also four sets of documents described as “Miscellaneous Top Secret” and three others listed as “Miscellaneous Secret.”
Aug. 11: Attorney General Merrick Garland says in a public address that the Justice Department had exhausted efforts to retrieve the material in other ways. “The department does not take such a decision lightly,” Garland said. “Where possible, it is standard practice to seek less intrusive means as an alternative to a search, and to narrowly scope any search that is undertaken.”
Aug. 26: A federal judge releases a heavily redacted affidavit in support of the government’s application for a warrant to search Mar-a-Lago. “The government is conducting a criminal investigation concerning the improper removal and storage of classified information in unauthorized spaces, as well as the unlawful concealment or removal of government records,” the affidavit said. The federal government said it sought to redact information to protect witnesses, the FBI and details of the Justice Department’s strategy.