What really happened to the Spilotro brothers only became publicly known in 2007 during the 'Family Secrets' mob trial.
In 1986, their bodies were found and identified in an Indiana cornfield, and, as reported by the Los Angeles Times, 'Investigators suspect that the two men 'died at or near' the grave.' This led Scorsese and Pileggi to envision the violent end for the brothers that is seen in the film. Scorsese and Pileggi had no way of knowing what really became of the character's real-life counterparts, Anthony and Michael Spilotro, because the full details of their murders were not revealed until long after the film came out.
