Attorney General Merrick Garland tapped Jack Smith, a longtime federal prosecutor and former head of the Justice Department's public integrity section, as special counsel to oversee the DOJ's investigation into former President Donald Trump's efforts to overturn the 2020 election results, as well as his handling of classified materials after leaving office.

"Mr. Smith is the right choice to complete these manners in an evenhanded and urgent manner," Garland said at a press conference in November 2022.

Trump was indicted on Aug. 1 on charges of undertaking a "criminal scheme" to overturn the results of the 2020 election by allegedly enlisting a slate of so-called "fake electors" targeting several states; using the Justice Department to conduct "sham election crime investigations"; trying to enlist the vice president to "alter the election results"; and doubling down on false claims of a stolen election as the Jan. 6 riot ensued -- all in an effort to subvert democracy and stay in power, according to Smith's prosecutors.

Trump told ABC News the charges were a "pile-on" and said "it's election interference" meant to keep him from winning back the presidency.

In June, Trump pleaded not guilty to 37 criminal counts related to his handling of classified materials, after prosecutors said he repeatedly refused to return hundreds of documents containing classified information ranging from U.S. nuclear secrets to the nation's defense capabilities. He has denied all charges and denounced the probe as a political witch hunt.

As special counsel, Smith will "exercise independent prosecutorial judgment to decide whether charges should be brought," Garland said while announcing Smith's appointment last year.

Smith said in a statement released in November through the Justice Department that he would "exercise independent judgment" and work "expeditiously and thoroughly to whatever outcome the facts and the law dictate."

"The pace of the investigations will not pause or flag under my watch," Smith said.

Former colleagues have characterized Smith as an aggressive prosecutor who would not shy away from taking on difficult prosecutorial judgments, with the background and temperament that make him a strong selection for the high-profile role.

"When it comes to investigating allegations of sophisticated federal criminal matters, Jack Smith is the gold standard," Edward J. Loya Jr., a former colleague in the public integrity section at the DOJ, told ABC News.

"He brings a tremendous amount of judgment, experience, and energy to the job and inspires those who work for him to do their best work. I am confident he will take on this role without fear or favor," said Loya, who is now at the law firm Epstein Becker Green.

Greg Andres, a former federal prosecutor who worked with Smith for more than a decade, lauded Smith as "uniquely qualified given his experience and his judgment."

"It's hard for me to think of a better choice -- he's independent, thoughtful, deliberate. He's going to do what's right and he has a tremendous amount of experience," said Andres, who is now at the law firm Davis Polk. "He'll turn over every stone, but he'll do it in a timely manner."

James McGovern, a former federal prosecutor with Smith in the Eastern District of New York, and now in private practice at Hogan Lovells, called Smith "the consummate prosecutor and public servant."

"I have no idea what his political beliefs are because he's completely apolitical," McGovern said. "He's committed to doing what is right."

Smith has most recently served since 2018 as chief prosecutor in the International Criminal Court (ICC) in The Hague, Netherlands, where he was tasked with investigating and adjudicating war crimes in Kosovo.

Prior to his time in the Hague, Smith served in multiple roles with the Justice Department, including as an assistant U.S. attorney in the Eastern District of New York and as first assistant U.S. attorney for the Middle District of Tennessee.

In 2010, Smith took the helm of the department's public integrity unit, where he oversaw high-profile cases that often targeted elected officials.

His section played a role in the failed prosecution of former senator and Democratic presidential candidate John Edwards for alleged campaign finance violations aimed at hiding an extramarital affair. Smith was chief when Edwards was indicted in 2011, but the DOJ dropped the case after a trial led to a deadlocked jury.

Smith has also demonstrated the capacity to drop cases when the evidence does not bear out a crime, former colleagues said, pointing to his decision to close a years-long case against former Rep. Tom Delay, R-Texas.

"If there is not a case, there will not be a case," said Brian Kidd, a former colleague at the Justice Department who is now a partner at Morrison Foerster. "He is not interested in prosecuting somebody for the point of prosecuting. If it moves to that next level, it's because the facts are there and he believes a crime was committed."

In 2014, House Republicans interviewed Smith as part of their investigation into whether the Obama-era IRS may have targeted conservatives for enforcement actions. Smith also oversaw the DOJ's subpoenaing of at least one reporter for testimony and documents about their sources -- a controversial practice that Attorney General Garland recently prohibited.

During his time in the Eastern District in New York, Smith prosecuted a man named Ronell Wilson for murdering two New York Police Department detectives. Wilson in 2006 became the first person sentenced to death since the reinstatement of the federal death penalty in 1988.

Smith is the second special counsel to investigate Trump, after former FBI Director Robert Mueller probed the Trump campaign's ties to the Russian government during the 2016 presidential campaign.

Andres, a former member of Mueller's team, said Smith will be an important figure not only in managing the investigation of Trump, but also symbolically as a figurehead for the probe.

"The most important thing is who is running the investigation -- think about it in the context of Robert Mueller," Andres said. "The story is Jack Smith."

Editor's Note: This story was originally published in November 2022 and has been updated.