According to Reuters, it was revealed in 2025 that Mueller had been diagnosed with Parkinson's disease several years earlier.
In 2017, he was appointed as special prosecutor to investigate the alleged interference of Russia in the elections that resulted in Donald Trump's victory. The investigation lasted two years and found that Russia did interfere, but no collusion with Trump or his team was established.
After his death, Donald Trump expressed his opinion on the social network Truth Social, noting that he was glad about this event.
