Special Counsel Robert Mueller is best known for leading the federal government's probe into Russian meddling and possible collusion with Trump associates during the 2016 election. But there's more to the 74-year-old than his involvement in the high-profile investigation.

Mueller’s long-awaited findings were detailed in Attorney General William Barr’s letter to Capitol Hill lawmakers. The four-page letter stated definitively that Mueller did not establish evidence that President Trump’s team or any associates of the Trump campaign had conspired with Russia to sway the 2016 election.

Mueller, who took over the probe in May 2017, has a storied career that ranges from Marine to FBI director.

MUELLER'S RUSSIA INVESTIGATION: WHAT TO KNOW

Here are three things to know about him that may surprise you.

Mueller played hockey alongside John Kerry

Mueller, while a student at St. Paul’s school in New Hampshire, was involved in various sports and served as captain of the school’s soccer, lacrosse and hockey teams, according to Biography. But perhaps most notably during his time on the hockey team, Mueller’s fellow teammate was none other than John Kerry, who would later serve as the U.S. Secretary of State from 2013 to 2017.

Mueller led the NFL’s Ray Rice probe

Speaking of sports, Mueller was tapped by the NFL to lead an independent investigation into its handling of the Ray Rice domestic violence case.

Rice, a former running back for the Baltimore Ravens, was suspended for two games by NFL commissioner Roger Goodell in 2014 after a video surfaced that purportedly showed him dragging his then-fiancée Janay Palmer from an elevator at an Atlantic City casino.

Later, TMZ released a video that showed a fuller story of the incident. In the video, the football star is seen hitting Palmer in the face, causing her to hit a handrail in the elevator. She was rendered unconscious as a result. His suspension was made indefinite after footage of the entire incident was made public.

In a 2018 interview with "CBS This Morning," Janay, who married Rice, said she doesn't have any intention of ever watching the tape.

HOW PAUL MANAFORT IS CONNECTED TO THE TRUMP, RUSSIA INVESTIGATION

He has a unique nickname at the Justice Department

Mueller — whose full name is Robert Swan Mueller III — reportedly has a unique nickname at the U.S. Justice Department in Washington, D.C.: “Bobby Three Sticks.”

WHO'S BEEN CHARGED BY MUELLER IN THE RUSSIA PROBE SO FAR?

The nickname has two meanings: It’s apparently a reference to the “III” at the end of his name but is also reportedly inspired by the Boy Scouts’ three-fingered salute.

Bonus:

Mueller made the shortlist for TIME magazine's person of the year in 2018.