WASHINGTON:  Robert S Mueller III, the FBI director who transformed the nation’s premier law enforcement agency into a terrorism-fighting force after the Sept 11, 2001, attacks and who later became special counsel in charge of investigating ties between Russia and Donald Trump’s presidential campaign, has died. He was 81.

“With deep sadness, we are sharing the news that Bob passed away” on Friday night, his family said in a statement Saturday. “His family asks that their privacy be respected.”

At the FBI, Mueller set about almost immediately overhauling the bureau’s mission to meet the law enforcement needs of the 21st century, beginning his 12-year tenure just one week before the Sept 11 attacks and serving across presidents of both political parties. He was nominated by Republican President George W Bush.