"Their actions to take over Kathleen's estate doesn't surprise me at all," Peterson said.
"We can't see how, if anyone was ever gonna be appointed, it would be these two," said Joel Brodsky, Peterson's attorney.
Savio's death was originally ruled an accident but has been re-classified as a homicide. She died in a bathtub.
Peterson has not been charged in that case or in the 2007 disappearance of his fourth wife, Stacy Peterson.