A Pennsylvania judge says mass murderer George Banks is too mentally ill to be executed.

Banks killed 13 people in a 1982 shooting rampage in northeastern Pennsylvania. Five of the victims were his own children.

Judge Michael Conahan agrees with defense attorneys that Banks is psychotic and unable to comprehend his death sentence or participate in his defense.

Conahan issued the ruling Monday, several weeks after a hearing on Banks' mental state.

The judge had decided once before that Banks couldn't be put to death. But the state Supreme Court ordered a fresh hearing after finding that Conahan improperly barred a prosecution psychiatrist from testifying.

Prosecutors concede Banks is mentally ill but maintain the execution should go forward.