Jackson, Miss. The U.S. Supreme Court is considering arguments from a former Ku Klux Klansman convicted in the 1964 slayings of three civil rights workers.
Edgar Ray Killen claims he was denied constitutional rights in his Mississippi trial.
State prosecutors had until the close of business Tuesday to respond to Killen's petition before the Supreme Court. Killen's attorney could offer a response to prosecutors' comments before the court rules.
Killen made the same arguments to a federal judge in Mississippi in 2012 and before the 5th U.S. Circuit Court of Appeals in New Orleans earlier this year. He lost in both courts.
Killen was convicted of manslaughter in 2005, 41 years after the deaths of Michael Schwerner, Andrew Goodman and James Chaney. He is serving 60 years in prison.