Motions filed in court by the attorneys cite irreconcilable differences with co-counsel Joel Brodsky.
The attorneys say going to trial would - violate their firm's ethical duty to zealously represent the best interests of the client.
The former Bolingbrook Police sergeant is in jail, charged with murder in the 2004 death of his third wife, Kathleen Savio.
Peterson's fourth wife, Stacy, vanished in October of 2007, but he has not been charged in connection with her disappearance.
