The former suburban Chicago police officer convicted of killing his third wife and suspected in his fourth spouse's disappearance pleaded not guilty Tuesday to charges he tried to hire someone to kill the prosecutor who helped put him in state prison.

Drew Peterson was charged in February with soliciting an unidentified person to find someone he could pay to kill Will County State's Attorney James Glasgow. One of Peterson's former attorneys last week released letters that he says show Peterson was set up.

The 61-year-old former Bolingbrook police sergeant appeared in court Tuesday in prison-issued clothing -- a white shirt and black pants. He waived his right to a preliminary hearing.

Peterson was polite, answering, "Yes, your honor" and "I understand, your honor," to the questions posed to him.

The Randolph County State's Attorney's office disclosed in court that the case against Peterson involved the use of a court-ordered eavesdropping device on two occasions.

Peterson has been in prison since being convicted in 2012 in Kathleen Savio's bathtub drowning death eight years earlier. His fourth wife Stacy Peterson disappeared in 2007.

The murder-for-hire charges were filed in Randolph County, where Peterson is an inmate at the Menard Correctional Center. Peterson's former attorney Joel Brodsky released information last week that he claimed showed Peterson was set up in the murder-for-hire plot.