Berman is a Republican who contributed to the president's election campaign, worked for the same law firm as Trump attorney Rudolph Giuliani and was put in his job by the Trump administration. But now, as U.S. attorney in the Southern District of New York, he is investigating numerous Trump allies and has won over some skeptics.
"Geoff has exceeded everybody's expectations," said Hadassa Waxman, a Democrat who recently left her job as co-chief of the U.S. attorney's General Crimes Unit, a post to which she was appointed by Berman's predecessor, Preet Bharara.
"From Day One, he went in there and said, 'This is going to be the Southern District. There's not going to be any change. I'm going to lead the office with the same integrity, commitment to fairness.'"
Berman, 59, was appointed by then-Attorney General Jeff Sessions in January 2018, months after Bharara was fired after refusing to resign along with dozens of other federal prosecutors appointed by President Barack Obama.
Three months later, FBI agents raided the offices of Trump's personal lawyer and fixer, Michael Cohen, an act the president decried as a politically motivated witch hunt. For reasons never explained publicly, the Justice Department decided Berman should recuse himself from supervising that investigation, putting it in the hands of his hand-picked top deputy, Robert Khuzami.
Since then, though, Berman has taken a direct hand in other investigations that have angered Trump. This month, Berman's office subpoenaed Trump's inaugural committee for a wide range of documents as part of an investigation into various potential crimes, including possible illegal contributions from foreigners to inaugural events.
Weeks before the midterm election, Berman announced insider trading charges against an ardent Trump supporter, Rep. Chris Collins, nearly ruining the Republican's re-election bid. Collins, who represents western New York, has pleaded not guilty.
Prosecutors in Berman's office have investigated campaign finance crimes committed when Cohen, sometimes working in conjunction with National Enquirer publisher American Media Inc., arranged payments to two women to stay silent about alleged affairs with Trump.
Asked Monday on Fox News whether the New York investigations posed any threat to the president, Donald Trump Jr. dismissed them as politically motivated. "They're not investigating actual crimes anymore. They're literally just trying to find something to make a big deal of," he said. "Their dream in life is to try to find something to get Trump. I mean, it's that old Stalinist tactic: Show me the man, I'll show you the crime."
That attack came just days after The New York Times referred to Berman as a "Trump ally." In its report, based on unidentified sources, the Times said Trump late last year had asked Matthew G. Whitaker, his acting attorney general at the time, if Berman could be put in charge of the seemingly widening Cohen probe. Trump called the story "fake news."
Mary Jo White, an independent appointed by President Bill Clinton to a stint as U.S. attorney in Manhattan from 1993 to 2002, said she spoke to Berman last week and he was upset at the newspaper's characterization of him.
"He is concerned anybody would even think for a moment he is anything but totally independent," White said. "Any time any of us have our integrity impugned it's upsetting. ... And it's so off and wrong in his case."
Mimi Rocah, who left the Southern District as a prosecutor two months before Berman arrived, said she believes some people were initially skeptical about anyone appointed U.S. attorney by Trump. But Rocah, now a criminal justice fellow at Pace University Law School, said Berman "has earned the trust of the rank-and-file prosecutors because he is not letting himself be influenced by political considerations, even if that is something Trump has tried to do."
Berman, who declined to be interviewed for this story, is known in his office for a dry wit, a hands-on approach to the job and compassion for those suffering death or illness in their families. Born in Trenton, New Jersey, Berman went to the University of Pennsylvania and earned his law degree at Stanford. From 1987 to 1990, he worked for the independent counsel who investigated the Reagan administration in the Iran-Contra affair.
After serving as a federal prosecutor from 1990 to 1994, Berman worked at a New Jersey law firm, then ran a minor-league hockey franchise owned by his father. Afterward, Berman joined Greenberg Traurig, the same law firm as Giuliani.
In 2016, he donated $5,400 to Trump's campaign, half of which was refunded because it exceeded the general election limit. When Berman's name surfaced as a candidate to become the U.S. attorney in Manhattan, Democratic Sen. Kirsten Gillibrand said he should be disqualified from the post because he had met with Trump for a brief job interview, which she said was inappropriate. His supporters noted that Bharara had also met with Trump at Trump Tower after the presidential election.
Trump never submitted Berman's name to the Senate for confirmation, but his appointment became permanent anyway after federal judges voted unanimously to keep him in the job. In addition to his office's other investigations, which are being conducted separately from special counsel Robert Mueller's Russia investigation in Washington, Berman has announced charges against a Russian lawyer who met with Donald Trump Jr. and Trump son-in-law Jared Kushner at Trump Tower in 2016 after an intermediary suggested she might have dirt on Hillary Clinton.
Berman is also presiding over anything his office might do regarding Amazon founder Jeff Bezos' claims that American Media tried to blackmail him by threatening to publish intimate photos of him. AMI is run by longtime Trump friend David Pecker.
Waxman said she was impressed how quickly the several dozen prosecutors she oversaw in the office took to Berman after he took charge. "The folks on the ground, in the weeds, have confidence in him," Waxman said. "He's not political."
Cohen, who pleaded guilty to tax evasion, bank fraud, campaign finance violations and lying to Congress, is testifying on Capitol Hill this week about his dealings with Trump.