Killen planned and directed the murders of James Chaney, Andrew Goodman, and Michael Schwerner, three civil rights activists participating in the Freedom Summer of 1964. He was found guilty in state court of three counts of manslaughter on June 21, 2005, the forty-first anniversary of the crime, and sentenced to 60 years in prison. He appealed against the verdict, but the sentence was upheld on April 12, 2007, by the Supreme Court of Mississippi. 