As head of the FBI's Minneapolis office the past three years, Richard Thornton has led the nation's largest terror recruitment case, tackled a Gambian coup attempt and stood vigil at the rural Stearns County dig site that brought somber finality to the search for Jacob Wetterling.

Now, before ending his 30-year FBI career this month, Thornton is leading his office's 180 agents in one more unexpected way: by parrying attacks on the bureau lobbed from some of the highest levels of government, including President Donald Trump.

"The FBI writ large, and in particular the part of the FBI I'm responsible for, we're doing the people's work," Thornton said in a recent interview with the Star Tribune. "Everything else out there is noise. ... It's based on half-truths and not an accurate depiction of what goes on here or at the FBI around the world."

Thornton said he has taken "a fairly active and engaged posture" with his workforce, which also extends to the Dakotas, to remind agents through daily briefings and staffwide memos "to tune out that noise."

"I think history will tell the final story on this," Thornton said of a moment he described as uniquely polarized. "When, I think, this period of time is viewed through a historical lens, a balanced perspective, I think the FBI will be looking just fine versus what we've sort of been under fire for now."

The FBI has not publicly announced a replacement for Thornton, who departs Feb. 28 after reaching the mandatory retirement age of 57. But his exit also sets up an unusual transition for Minnesota law enforcement, as new leadership will be taking over at each federal agency's local wing with the state still waiting for a new U.S. attorney.

Minnesota federal law enforcement officials, past and present, single out the relationship between the FBI's special agent in charge and U.S. attorney as a vital partnership capable of either underpinning or derailing any of the state's most crucial investigations.

Few cases required this as urgently as the probe that landed a dramatic 2016 confession from Danny Heinrich, Wetterling's killer. Former U.S. Attorney Andrew Luger remembers at the outset of the case telling Thornton — after meeting with Stearns County law enforcement in a conference room named for Jacob — that he wanted to poll the room on whether authorities believed they had the right suspect.

"He was very calm," Luger said, "and he said, 'Ask all the questions you want. But I know what the answers are.' "

He 'gets Minnesota'

A Missouri native, Thornton's last stop with the FBI is his second in Minneapolis, and he now says he wants to stay here upon leaving the bureau. Thornton's return to the Minneapolis office is owed partly to a request by Luger to then FBI Director James Comey that he appoint a top agent "who gets Minnesota."

Thornton said he first considered becoming an agent after a college professor brokered a meeting with the St. Louis FBI head in the mid-1980s. Thornton eventually swapped his pursuit of an MBA for a job piloting surveillance aircraft. Before his return to Minneapolis in 2014, Thornton went on to manage that section for the FBI's Critical Incident Response Group at headquarters, which played key roles in high-profile abduction cases and thwarted terror attempts.

From international terrorism to threats against places of worship, Thornton had led FBI teams through an eventful stretch.

He managed key civil rights cases as a supervisor in the early 2000s in Washington, D.C. First, he helped oversee a successful cold-case investigation of the fatal 1963 16th Street Baptist Church bombing in Alabama. And the morning after the 9/11 attacks, Thornton helped the agency gird for an unprecedented wave of hate crimes against Muslim and Sikh communities across the country.

"Even though you don't necessarily realize it at the time, every one of those experiences helps you," Thornton said.

In Minnesota, Thornton has visited mosques to talk security after last year's bombing at a Bloomington Islamic center. Last spring, he helped broker outreach to the Jewish community when a wave of bomb threats rattled the country. And Luger said Thornton persuaded him to rip up a canned statement in favor of a public meeting to address renewed concerns of backlash among local Muslims after a 2016 terror attack in Belgium.

"He has the ability to address the situation calmly, with composure and compassionately," said Steve Hunegs, director of the Jewish Community Relations Council of Minnesota and the Dakotas. "As you know, law enforcement is limited in what they can say, but sometimes the tone is as important as the substance."

Stephen Thomason, an FBI special agent in Mississippi who worked for Thornton in Missouri in the mid-2000s, said Thornton had a knack for managing agents while giving the impression that he was still one of them. Thornton regularly joined rank-and-file agents on late-night surveillance runs and at the shooting range for target practice, Thomason said.

"If we were out working, Rick was going to be working. If his guys were out, he was going to be out," Thomason said. "Not getting in the way, not micromanaging, but making sure he knew they had what was needed to get the job done."

The Wetterling mystery

More than a decade later, on the verge of solving the 27-year mystery of Jacob Wetterling's disappearance, Thornton spent hours at the dig site, texting Luger updates when investigators unearthed Jacob's red jacket and, eventually, his remains. A veteran of marathon terrorism surveillance missions, Thornton described the 10 days that led to Heinrich's confession as the most stressful of his career.

"The flip side was that through my interactions with Patty and Jerry Wetterling ... I knew they still held out some hope that all these years later that Jacob would be found safe," Thornton said.

Though a calm, quiet presence in meetings, Thornton's role in the search was not lost on the Wetterlings.

"What I saw in him was his absolute commitment to finish this, and that was huge," Patty Wetterling said. "So many people worked so hard for a very long time, but this was the time. He had that steely commitment that everybody had to have or we would have never gotten the answers."

FBI officials said Thornton also led monthly meetings for Minnesota's large Joint Terrorism Task Force even though most of the country's other JTTFs meet on a quarterly basis. And under Thornton, the FBI led a rare set of use-of-force trainings for police agencies after a federal civil rights investigation into Jamar Clark's police shooting death in Minneapolis.

Thornton lists international terrorism recruitment, gangs, crime in Indian Country, cyberthreats and, increasingly, far-right domestic extremism as among the priorities his successor will inherit this spring. But Minneapolis' next FBI chief may also be thrust into unexpected roles, like bridging the gap during a sudden dismissal of a U.S. attorney.

U.S. Attorney Greg Brooker, who has led the office on an interim basis since Luger's forced resignation under the Trump administration last March, credited Thornton's help in getting up to speed on key cases after being asked to take over the office on "very short notice."

"It was important to federal law enforcement that we have a smooth transition," Brooker said. "Due to Rick's great partnership, it was very smooth indeed."