PIERRE, S.D. (AP) - The South Dakota Supreme Court has overturned a state prison inmate's death sentence for the killing of a prison guard nearly two years ago.

Justices say Rodney Berget must get a new sentencing hearing because the circuit judge who sentenced him to die improperly considered statements Berget made to a psychiatrist.

Berget and another inmate, Eric Robert, pleaded guilty to killing prison guard Ronald Johnson during a failed escape attempt in April 2011 at the South Dakota State Penitentiary in Sioux Falls. Robert was executed by lethal injection last October. Berget appealed his death sentence.

A third inmate, Michael Nordman, was given a life sentence for providing materials used in the slaying.