Will County Judge Stephen White said he already warned more than 200 potential jurors to avoid media reports about the case and will send them a letter reminding them of the admonishment.
"We've done everything we can to protect the integrity of the proceedings," White said.
Peterson, a former Bolingbrook police officer, has pleaded not guilty to first-degree murder in the 2004 death of Kathleen Savio, whose body was found in a dry bathtub.
Savio's death was originally ruled an accident. But after Peterson was named a suspect in the disappearance of his fourth wife, Stacy Peterson, in October 2007, Savio's body was exhumed. Her death was ruled a homicide after a new autopsy was conducted.
A Jan. 19 hearing is scheduled to determine what, if any, hearsay evidence will be allowed at trial. White left open the possibility he could close the hearing for specific evidence or specific witnesses.
An attorney for Peterson, Joel Brodsky, argued that it "will be impossible for jurors to avoid" media coverage of the hearing.
But Will County State's Attorney James Glasgow said case law was on the prosecution's side. And, he said, "Nobody can pull a fast one, because everybody is watching."
The Illinois Legislature passed a law allowing hearsay evidence to be admitted at murder trials in response to the Peterson case, essentially allowing Savio to testify from beyond the grave.
Glasgow said 60 witnesses may be called, although he did not identify them. Several people, including Savio's sister, have told authorities that Savio feared for her life. And Savio herself said in court papers that she feared Peterson would kill her.
In addition, a minister has told authorities that Stacy Peterson confided in him that her husband admitted killing Savio.
Peterson is being held on $20 million bond.
