Who was donnie brasco based on?

Donnie Brasco is based on the true story of an undercover FBI agent named Joseph D. Pistone, who infiltrated the Mafia during the 1970s. He assumed the alias "Donnie Brasco" while gathering evidence against the Bonanno crime family. The operation eventually led to numerous arrests and convictions, highlighting the challenges and dangers of undercover work in organized crime. The story was later adapted into a film starring Johnny Depp and Al Pacino.