Which actor played Raymond, an autistic savant in the film "Rain Man"?

Rain Man is a 1988 American comedy-drama film directed by Barry Levinson and written by Barry Morrow and Ronald Bass. It tells the story of abrasive, selfish young wheeler-dealer Charlie Babbitt (Tom Cruise), who discovers that his estranged father has died and bequeathed all of his multimillion-dollar estate to his other son, Raymond (Dustin Hoffman), an autistic savant, of whose existence Charlie was unaware. Charlie is left with only his father's beloved vintage car and rosebushes. Valeria Golino also stars as Charlie's girlfriend Susanna.

Morrow created the character of Raymond after meeting Kim Peek, a real-life savant; his characterization was based on both Peek and Bill Sackter, a good friend of Morrow who was the subject of Bill, an earlier film that Morrow wrote.