In the Spirit of Crazy Horse is a book by Peter Matthiessen which chronicles "the story of Leonard Peltier and the FBI's war on the American Indian Movement." It was first published in 1983. Leonard Peltier was convicted of murder in 1977 and sentenced to life in prison for the 1975 killing of two FBI agents, after a trial which the author and many others allege was based on fabricated evidence, widespread fraud and government misconduct.