Robert S. Mueller III, the former FBI director who led the investigation into Russian interference in the 2016 election and its potential ties to President Donald Trump, died Friday at age 81. His death marks the end of a career defined by rebuilding the FBI after 9/11 and confronting a sitting president.

Mueller became director just days before the September 11th attacks and transformed the bureau into a modern intelligence agency while exposing CIA torture programs. He was appointed special counsel in May 2017, eight days after Trump fired FBI Director James Comey, who was leading the Russia probe. Trump's fury at Mueller was palpable, calling the investigation a "WITCH HUNT!" Mueller's team secured convictions against Trump associates like Paul Manafort and Roger Stone, but he ultimately declined to indict Trump for obstruction of justice, stating the Justice Department's position that a sitting president cannot be charged.

His investigation reversed public perceptions of the FBI, earning praise from liberals and scorn from conservatives. Mueller's legacy is one of institutional integrity amidst political turmoil.