Following Robert Mueller’s Death at 81, a Look at His Legacy

Before Robert S. Mueller III led the FBI in the 9/11 era or investigated Russian interference in the 2016 election as special counsel, the U.S. Marine and Vietnam veteran tried his hand working as a lawyer in the private sector.

Mueller took a job at a prestigious, high-paying law firm in the 1990s — and he hated it. So he quit, taking a substantial pay cut to become a line prosecutor working homicide in Washington, D.C.

“His great joy was putting away bad guys and answering his phone, ‘Mueller, Homicide,’” Marc Fisher, then of The Washington Post, said in FRONTLINE’s 2019 documentary The Mueller Investigation.

“Bob Mueller cares about one thing, and one thing only: indicting bad guys and putting them in prison,” Michael Isikoff, then of Yahoo! News, said in the film.

In light of Mueller’s recent death at age 81, The Mueller Investigation and FRONTLINE’s other reporting involving Mueller offer insights into his legacy and his long career in public service — from his time running the FBI under both Presidents George W. Bush and Barack Obama, to the probe of Russian election interference that put him on a collision course with President Donald Trump.

Sworn in as FBI director a week before the Sept. 11, 2001, attacks, Mueller went on to revamp the agency with a focus on counterterrorism. In a 2003 interview with FRONTLINE, he spoke about his approach and why he saw the Patriot Act as an important tool despite criticism that it could increase the potential for civil liberties abuses.

“In order for us to be effective in this day and age where the globe has gotten smaller, where terrorists can move effectively across borders, we have to effectively exchange information with the intelligence counterparts who have the principal mission of developing intelligence overseas,” Mueller said in the interview.

“The FBI’s principal priority right now is protecting the United States against another terrorist attack,” Mueller said.

But Mueller also grew concerned that a controversial NSA surveillance program was violating constitutional protections against illegal search and seizures, and threatened to quit over it in 2004 — a scene recounted in the 2014 FRONTLINE film, United States of Secrets.

While Mueller was credited with modernizing the FBI, some of the agency’s terror investigations were also criticized for overreaching, including the prosecution at the heart of the 2021 FRONTLINE documentary In the Shadow of 9/11.

Years later, the Department of Justice would appoint Mueller as special counsel to lead the investigation that became central to President Trump’s first term, and that Trump continually described as a “witch hunt.”

Trump adviser Steve Bannon told FRONTLINE in The Mueller Investigation, “He was announced as special counsel, and I just go, ‘Oh my God. This is going to be a grind, because this is a guy that doesn’t leave any stone unturned.’”

“This is a guy who has no problem with holding people accountable, being direct and driven to get the answer,” retired FBI special agent Frank Montoya, Jr. said in the film. “That he’s going to do it right, you know, in accordance with the rule of law. That’s all that matters.”

Explore FRONTLINE’s collected reporting below:

• Read a 2003 interview with Mueller from Chasing the Sleeper Cell