 A man charged with killing a woman and her adult son in Ottertail County has been found incompetent to stand trial and will be committed to a secure treatment center in St. Peter. 22-year-old William Hillman will be held at a center until his mental health improves and he is able to take part in legal proceedings against him. Hillman is charged in the deaths of 42-year-old Denise McFadden and 21-year-old Dalton McFadden. They were found fatally beaten at their rural Purim home last April. Authorities say Hillman was released from the mental health commitment in November of 2017 after punching his mother and threatening to kill her. He moved in with the McFaddens about six weeks before they were killed.