Joliet, Illinois (CNN) -- Former police officer Drew Peterson will remain in jail while prosecutors pursue an appeal that has delayed the start of his first-degree murder trial, a judge ruled Thursday.
Peterson's attorneys demanded his immediate release after prosecutors announced they would challenge Will County Circuit Judge Stephen White's refusal to reconsider a pre-trial ruling that barred them from introducing some witnesses' statements. Jury selection had been scheduled to start Thursday, but the appeal is likely to delay the trial for weeks, perhaps months.
Peterson has pleaded not guilty to first-degree murder in the 2004 death of his third wife, Kathleen Savio. A former police sergeant in Bolingbrook, on the outskirts of Chicago, Peterson has been held in lieu of $20 million bond since May 2009.
Savio's death initially was ruled an accidental drowning, but her body was exhumed and re-examined in 2007 after the still-unsolved disappearance of Peterson's fourth wife, Stacy. Peterson denies any wrongdoing in either case, and defense attorney Joel Brodsky told reporters Wednesday that the state's appeal is a tacit admission that "they don't have a case" without hearsay.
In Session Correspondent Beth Karas contributed to this report.