Factbox-Timeline of key events in Trump document probe

WASHINGTON (Reuters) - The U.S. Department of Justice on Tuesday laid out its evidence of obstruction of justice in the ongoing investigation of government records stored at former President Donald Trump's Florida residence after he left office.

Federal prosecutors, in a court filing, alleged publicly for the first time that Trump's records custodian, who was unnamed, falsely certified that the former Republican president had returned all the government records. The department also said it had evidence classified documents were deliberately concealed from the FBI.

The National Archives and Records Administration (NARA), in various letters, said it "had ongoing communications with the former president's representatives throughout 2021 about what appeared to be missing presidential records," now the subject of an ongoing federal investigation

Below is a timeline of key events in the probe:

Jan. 20, 2021

Trump departs the White House as Democrat Joe Biden is sworn in as the nation's 46th president and heads back to his private Florida estate known as Mar-a-Lago.

May 2021

The Archives emails Trump's lawyers, notifying them that some two dozen boxes of original records were not turned over, according to the Washington Post https://www.washingtonpost.com/national-security/2022/08/24/trump-records-archives-2021/.

December 2021

A Trump "representative" tells the Archives "that they had located some records," according to statement https://www.archives.gov/press/press-releases/2022/nr22-001 published later by NARA.

Mid-January 2022

The Archives retrieves 15 boxes https://www.archives.gov/press/press-releases/2022/nr22-001 of presidential records from Trump's estate.

The nonpartisan presidential records agency said it "identified items marked as classified national security information, up to the level of Top Secret and including Sensitive Compartmented Information and Special Access Program materials" and sought permission to alert the FBI.

Feb. 8, 2022

The Archives issues a public statement saying it is still searching for more of Trump's presidential records, one day after the Washington Post reported https://wapo.st/3opJziD the boxes were retrieved from Florida.

Feb. 10, 2022

U.S. House of Representatives Oversight Committee announces an investigation into Trump's handling of the documents, later expanding its probe in a Feb. 24 letter to the agency.

The New York Times reports White House staff periodically found clumps of documents clogging White House toilets, an accusation Trump has said is false. Reporter Maggie Haberman later releases photos https://www.axios.com/2022/08/08/trump-toilet-photos-maggie-haberman of some of the alleged found documents.

Feb. 18, 2022

NARA tells Congress that Trump took classified information to his Florida home after leaving the White House.

April 7, 2022

Sources confirm to Reuters that the U.S. Justice Department was investigating Trump's removal of official presidential records from the White House.

April 11, 2022

The White House Counsel's Office under Biden formally requests that the Archives give the FBI access to the 15 boxes. NARA notifies Trump's representatives about the FBI review in an April 12 letter.

April 29 and May 1

Trump lawyer Evan Corcoran seeks to delay disclosure to the FBI in two letters sent to the Archives.

May 10, 2022

Acting U.S. Archivist Debra Steidel Wall responds to Corcoran, rejecting Trump's requested delay and refusing his "'protective' claim of privilege," adding the FBI can access the records as soon as May 12. The letter is made public Aug. 23 and notes hundreds of pages of classified documents were recovered so far.

May 11, 2022

Jay Bratt, chief of counterintelligence and export control at the U.S. Justice Department's National Security Division requests Trump's custodian of records appear before a federal grand jury in Washington, Tuesday's filing showed. Bratt, in a separate letter to Corcoran, says the representative can comply with the subpoena by giving the FBI "any responsive documents" and a sworn statement, instead of appearing in court. The grand jury probe is first reported by the New York Times.

June 3

A Trump representative, whose name is redacted in the Justice Department filing, asserts that "a diligent search" was conducted for documents at Mar-a-Lago removed from the White House and that "any and all responsive documents accompany this certification."

Aug 8

Federal agents execute a search warrant at Trump's Florida property, uncovering 13 boxes or containers with documents marked classified --"more than twice the amount produced June 3 in response to the grand jury subpoena." Trump was not at the property at the time, and media reports showed him at Trump Tower in Manhattan.

A photo released in Tuesday's filing shows some of the seized documents with clear markings of "Top Secret" and "Secret."

Trump, in a post online, says the records were "all declassified" and placed in "secure storage." A day later, Trump, who continues to hint at a possible 2024 run for the presidency, cites the FBI search in a campaign fundraising appeal.

Aug. 12

The FBI's search warrant is released to the public following approval by U.S. Magistrate Judge Bruce Reinhart.

Aug. 22

Two weeks after the FBI's search, Trump separately asks the U.S. District Court for the Southern District of Florida for a so-called special master to review the documents, prompting the Justice Department's 54-page response on Tuesday.

The next day, the Archives releases its May 10 letter to Trump's attorney

Aug. 26

The Justice Department releases a heavily redacted affidavit -- a sworn statement outlining the evidence giving law enforcement officials probable cause to ask a judge to approve a search warrant -- after media outlets sued for its release. A judge approved its release.

Aug. 30

The department files its response to Trump's request for a special master review.

Sept. 1

U.S. District Judge Aileen Cannon in West Palm Beach is scheduled to hold a court hearing on Trump's request regarding the documents -- nearly 19 months since he left office.

(Reporting by Sarah N. Lynch, Doina Chiacu and Susan Heavey; Editing by Richard Cowan and Jonathan Oatis)