Michael Yarnell pleaded guilty to first-degree involuntary manslaughter in the 2003 death of his wife, Angie Yarnell, as part of a plea agreement in 2009.
He said he shoved her off of the deck of their Ivy Bend home and then lost the body in a canoe.
Yarnell got out of prison Monday on conditional release.
Angie Yarnell's mother, Marianne Asher-Chapman of Holts Summit, is not happy about his release and feels that he is a danger to society. "He is a dark person; he doesn't show emotion in any way, not an inch of emotion. I think it's a matter of time before he offends again."
The body of Angie Yarnell has still not been recovered.