The Lifetime channel will air "Drew Peterson: Untouchable" at 7 p.m. on Saturday.
State's Attorney Jim Glasgow, the man trying to prosecute the real-life Peterson for Savio's murder, said he'll be tuning in, but not by choice.
"Obviously I have to watch it," Glasgow said.
He said his office has to be aware of any publicity in the case - "for obvious reasons." Glasgow said Lifetime's movie won't hurt his case, but he didn't want to talk about the footage he's seen so far. The case is on hold pending appeals.
"Untouchable" is based on the book "Fatal Vows: The Tragic Wives of Sergeant Drew Peterson" by former Joliet Herald-News reporter Joe Hosey. It stars Kaley Cuoco as Peterson's missing fourth wife Stacy Peterson, Cara Buono as Savio and Rob Lowe as Peterson.
Stacy Peterson was last seen on October 28, 2007. Drew Peterson is a suspect in her disappearance but has never been charged. He is being held in jail on charges he killed Savio and is awaiting trial.
(Sun-Times Media Wire contributed to this report)