Ron and Dan Lafferty belonged to the mainstream Mormon faith until they studied the history of the early Mormon movement and converted to Mormon Fundamentalism. Initially, Dan led many of his family members into an extreme and literalistic interpretation of Mormonism. His brother Ron, in an attempt to intervene, was converted to the family's cause and became their religious leader. Over time, Ron penned several revelations, including a revelation that the wife of his brother, Alan Lafferty, was to be "removed" for opposing the brother's fundamentalist movement. Ultimately, Ron and Dan brutally murdered their sister-in-law Brenda and her infant daughter, their niece. Ron and Dan intended to murder several others, but were arrested before they could carry out the rest of the prophecy. Incomprehensibly, several of their followers, including Alan himself, were aware of the fatal prophecy, and yet they failed to oppose Ron's prophetic authority and the alleged will of God. Throughout it all, the Laffertys believed that God was guiding them in all their actions.  

Learn More:

• Wikipedia - Utah v. Lafferty
• Wikipedia - Under the Banner of Heaven
• Deseret News - 1984 Lafferty case still haunts