Federal authorities entered uncharted territory on Monday when they raided former President Donald Trump's Mar-a-Lago estate in search of evidence reportedly tied to Trump's alleged mishandling of government documents, setting off renewed speculation about his potential legal exposure.
And while no precedent exists to guide a criminal probe of a former president, a small number of recent cases involving senior government officials improperly retaining classified information could serve as a roadmap for prosecutors if an ongoing FBI probe bears evidence of criminal conduct, legal experts told ABC News.
"At the end of the day, in evaluating whether to bring charges, the Justice Department would compare the facts they think they can prove beyond a reasonable doubt to the facts at issue in past cases," said David Laufman, a former Justice Department official in the national security division and current partner at Wiggin and Dana LLP.
The stunning FBI raid on the former president's Florida home was related to documents that Trump took with him when he departed Washington in January 2021, including some records the National Archives has said were marked classified, sources told ABC News.
In January 2022, Trump turned over 15 boxes of records to the National Archives, but a small team of federal agents followed up with Trump's lawyers in the spring to inquire about additional records he may have removed from the White House. Attorneys for Trump said they were in the process of searching for documents and had been engaged in some back-and-forth communications with federal investigators, sources told ABC News.
Trump, who has not been charged with a crime, slammed Monday's raid as "prosecutorial misconduct" and an "assault" orchestrated by his political foes.
Officials have thus far not disclosed what documents the federal agents had hoped to find, nor whether Trump had knowingly withheld any records.
Neither the Justice Department nor the FBI have commented on the record about the raid.
Experts suggested that investigators would be looking for possible evidence of two potential infractions: a violation of the Presidential Records Act, or a violation of various statutes dictating the mishandling of classified documents.
Both are seldom pursued and even more rarely prosecuted.
Without much precedent to rely on, legal experts said investigators may turn to past cases with overlapping elements to determine whether Trump violated the law.
One notable recent example cited by legal experts pertains to Gen. David Petraeus, the former CIA director who pleaded guilty in 2015 to a misdemeanor charge of mishandling classified information.
The charge was linked in part to documents that the former spy chief provided to his then-mistress, Paula Broadwell -- meaning that Petraeus not only illegally retained classified documents, but that he also shared them with others. Petraeus was sentenced to two years' probation and a $100,000 fine. Trump later considered him for the position of defense secretary.
There is no evidence Trump has improperly shared any classified documents.
Experts also pointed to the prosecution of Sandy Berger, a one-time national security adviser to President Bill Clinton, as another example of a high-profile official who faced criminal charges for mishandling classified information.
Berger pleaded guilty in 2005 to a misdemeanor charge of unauthorized retention of classified materials from the National Archives, after he stuffed classified documents into his pants and socks prior to testifying to the 9/11 Commission. Berger was fined $50,000 and sentenced to two years' probation.
'Blessed and cursed'
Howard Sklamberg, a former public integrity prosecutor with the Justice Department who helped prosecute Berger, said cases like these underscore the unusual challenges the government faces in probes targeting upper-echelon officials.
For high-profile officials like Trump, Sklamberg said the government's handling of the case can "cut both ways."
"On the one hand, the bigger the figure involved, the more resources the government uses to investigate. But on the other hand, the more care they take in deciding whether to charge you," said Sklamberg, who is now a partner with Arnold & Porter. "You're blessed and cursed as a higher-level person."
A lesser-known case that may foreshadow investigators' approach to Trump is that of Harold Martin, an intelligence contractor who over the course of more than two decades illegally took troves of physical and digital government documents -- some of which were categorized as sensitive compartmented information (SCI), the highest level of sensitivity. Martin was sentenced to nine years in prison in 2019 after pleading guilty to willful retention of national defense information.
David Aaron, a former Justice Department counterespionage official who prosecuted the case against Martin, said investigators will make a priority of determining why Trump would want to withhold certain records -- particularly given his unique access to the government's most closely held secrets.
"You see this with contractors, you see it with mid-level civil servants, and now we have this situation -- and you ask yourselves, why is a particular target doing this?" said Aaron, now senior counsel at Perkins Coie. "Some people latch onto classified information and just want to keep it. But then, with any given target who takes classified information, there is the potential for something more nefarious."
"With presidential documents, it's not like there are a million copies," Aaron added. "A high-level official could be keeping the only copy that exists, or one of only a few copies."
Other political figures have attracted scrutiny in recent years over allegations of mishandling classified information, but never faced criminal charges.
The FBI aggressively pursued allegations that former Secretary of State Hillary Clinton had maintained emails containing classified documents on a private server during her bid for the presidency, and announced developments in the case in the month leading up to the 2016 election. Clinton never faced charges, but then-FBI Director James Comey called her conduct "extremely careless."
Trump repeatedly called for the Justice Department to prosecute Clinton over her alleged retention of classified emails during the 2016 campaign, and continued to do so after taking office. On Monday, in his statement criticizing the raid on Mar-a-Lago, Trump again lamented Clinton's lack of culpability.
"Absolutely nothing has happened to hold her accountable," Trump said.