In eastern Iowa, a man who says he grew marijuana to treat his cancer has been found guilty of drug charges. The Quad-City Times reports a jury returned the verdict Wednesday for 48 year-old Benton Mackenzie in Scott County District Court. His wife and adult son were also found guilty of drug charges. The charges were in connection to dozens of marijuana plants found at Mackenzie's parents' home last year. Mackenzie said he wanted to testify in his trial that he grew the marijuana to treat a rare cancer condition with oil derived from the plant. A judge denied his motions to use that defense.