Recently filed court documents obtained by the paper indicate Steven Powell, 63, is scheduled to be released on March 23.
Susan Powell disappeared from her Utah home in 2009. Her husband Josh was a focus of the investigation until he killed himself and the couple's two children in an explosive house fire in February 2012.
Steven Powell was arrested after authorities investigating Susan Powell's disappearance searched his home and discovered he had recorded images of two neighbor girls, then ages 8 and 10, in their bathroom. He was convicted of 14 counts of voyeurism and was sentenced to 2 2/12 years in prison.
In May 2013, police in Utah opened their books on the investigation into Susan Powell's disappearance and announced they couldn't solve the sensational case. Authorities announced Josh Powell likely had an affair in the months before his wife disappeared. They also said Josh Powell and his brother Michael Powell are believed to be responsible for the disappearance, but said they never had enough evidence to bring charges.
Michael Powell killed himself in Feb. 2013 by leaping from a parking garage in Minneapolis.
Following Steven Powell's release from prison, he will be put on probation for 30 months, reports the Deseret News.
The girls Powell was convicted of taking pictures of were awarded $1.8 million in a civil judgment. In December 2013, a judge ordered authorities to sell Powell's home in Puyallup, Wash. to start paying off his debt. Powell is currently fighting to keep his home from being put on the auction block, according to the paper.
There is an ongoing federal investigation into the disappearance of Susan Powell. Susan Powell's father said in May 2013 that the federal probe could involve determining what Steven Powell knew about his daughter-in-law's disappearance.