The Pennsylvania Superior Court has rejected attempts by Philadelphia District Attorney Larry Krasner’s office to enforce an unusual post-conviction plea deal that was entered into more than 30 years ago and would have converted a defendant’s life sentence to, at most, a 25-year prison term.

The three-judge Superior Court panel, ruling unanimously in Commonwealth v. Chimenti, determined that the prosecutors’ request to enforce the deal, which the state Supreme Court subsequently took issue with, was an attempt to “usurp” the judiciary.