The estate of a southeast Iowa couple killed by their son has been auctioned off to seven buyers for nearly one million dollars. Sandra and Michael Bentler, and their three daughters we’re killed in 2006 at their home in rural Bonaparte. Their son Shawn was convicted of the slayings in 2007. The 445 acre estate was divided into seven tracts of land. One included the Bentler home and 28 acres of surrounding land. State law prohibits those convicted of murder from benefiting from their victims’ deaths.