An assistant district attorney who successfully prosecuted an Aryan Brotherhood case was appointed interim D.A. in Kaufman, Texas, on Monday in the wake of the murder of Mike McLelland, who was shot and killed along with his wife in their home on Saturday. Gov. Rick Perry will appoint McLelland’s successor. Investigators have turned their attention to the Aryan Brotherhood in the McLellands’ deaths, especially since the gang controls the methamphetamine trade in Kaufman. But investigators also cautioned against assuming the Aryan Brotherhood’s guilt, and others have speculated that the McLellands’ could have been killed by Mexican drug cartels. Autopsies on both McLellands were performed Monday, but the results have not yet been released.