By Sarah N. Lynch

WASHINGTON Jack Smith, the U.S. special counsel who has pursued criminal charges against former President Donald Trump over retention of classified government records, has earned a reputation for winning tough cases against war criminals, mobsters and crooked cops.

Appointed last November by Attorney General Merrick Garland to take over two Justice Department investigations involving Trump, Smith now has made history as the first federal prosecutor - though not the first prosecutor - to secure an indictment against a current or former U.S. president.

Manhattan District Attorney Bragg in April charged Trump with 34 felony counts of falsifying business records involving hush money paid to a porn star before the 2016 U.S. election.

When Smith is not busy competing in Ironman swim-cycle-run triathlon races, according to his former colleagues, he is working as a dogged investigator who is open-minded and not afraid to pursue the truth. They described him as just as tenacious in seeking to have criminal charges dropped for the innocent as he is to win convictions of the guilty.

"If the case is prosecutable, he will do it," said Mark Lesko, an attorney at the firm Greenberg Traurig LLP who worked with Smith when both were prosecutors at the U.S. Attorney's Office in New York. "He is fearless."

This case is unlike any other that Smith has brought because of who is being charged. Trump served as president from 2017 to 2021 and is now seeking to return to the White House, leading a crowded field of candidates seeking the 2024 Republican presidential nomination.

One of the two investigations that Smith took over involved Trump's handling of classified documents he retained after leaving the White House in January 2021. The second examined efforts to overturn the results of the 2020 U.S. election that Trump lost including a plot to submit phony slates of electors to block Congress from certifying Democrat Joe Biden's victory.

Grand juries in Washington have been hearing testimony from witnesses in recent months for both investigations.

Trump's own attorney Evan Corcoran emerged as a key witness in the documents investigation. Corcoran was compelled to testify before a grand jury in March after a federal judge ruled that his conversations with Trump were not shielded by a legal doctrine called attorney-client privilege - which protects the confidentiality of certain communications between lawyers and their clients - if Trump's comments were made in furtherance of a crime.

The election interference investigation - in which former Vice President Mike Pence and others who served in top roles in Trump's administration have been subpoenaed - remains ongoing.

SEARCH FOR INNOCENCE AND GUILT

Smith, a Harvard Law School grad who is not registered with any political party, started as a prosecutor in 1994 at the Manhattan District Attorney's Office under Robert Morgenthau, who was best known for prosecuting mob bosses.

"There was just a real emphasis, from Morgenthau on down, on not just going after convictions," said Todd Harrison, an attorney at the firm McDermott Will & Emery who worked with Smith in Morgenthau's office and later as a federal prosecutor.

"We were praised if we investigated something and demonstrated that the target of the investigation was innocent," Harrison added.

In 1999, Smith started working at the U.S. Attorney's Office in Brooklyn.

Smith was involved in the prosecution of Charles Schwarz, one of several former New York City police officers who were implicated in a high-profile police brutality case involving Abner Louima, a jailed Black inmate who had been assaulted by police with a broomstick.

Smith also won a murder conviction against Ronell Wilson, a drug gang leader who murdered two undercover New York City police officers, though a federal appeals court vacated the death penalty verdict.

In 2008, Smith left to supervise war crime prosecutions at the International Criminal Court in The Hague. He returned to the Justice Department in 2010 to head its Public Integrity Section until 2015.

More recently, Smith returned to war crimes cases in The Hague, winning the conviction of Salih Mustafa, a former Kosovo Liberation Army commander who ran a prison where torture took place during the 1998-99 independence conflict with Serbia.

(Reporting by Sarah N. Lynch; editing by Andy Sullivan and Will Dunham)