Calgary man who killed wife and entombed her in cement sentenced to 7 years in prison With the time he's already spent in custody, he has about two years and 10 months left to serve. He had argued he acted in self-defence when he killed his common-law wife, Lisa Mitchell, in 2012. Lisa Mitchell's body was found by police two years after she disappeared inside a plastic bin that had been covered by cement in a corner of the couple's basement. Mitchell was last seen in Calgary in October 2012.