Steven Powell is due to be released Sunday from the Washington state prison where he's been serving 30 months for voyeurism.
Department of Corrections spokeswoman Norah West said Monday that Powell is scheduled to complete his sentence March 23.
Powell is the father-in-law of Utah mother Susan Cox-Powell, who disappeared in 2009. His son, Josh Powell, was a suspect before he killed himself and his two children in an explosive house fire in 2012.
Steven Powell was convicted of voyeurism for taking photographs of two young neighbor girls as they used the bathroom in their home.
West says Powell will living in Tacoma and under community supervision. He'll be required to wear a GPS locator for at least 30 days, as well as attend sex offender treatment.