JDL speaks of how church members justified violence on orders from church leaders.
John D. Lee, Mormonism unveiled; or, The life and confessions of the late Mormon bishop, John D. Lee (St. Louis: Bryan, Brand & Co., 1877), 279-280
The Mormons nearly all, and I think every one of them in Utah, previous to the massacre at Mountain Meadows, believed in blood atonement. It was taught by the leaders and believed by the people that the Priesthood were inspired and could not give a wrong order. It was the belief of all that I ever heard talk of these things—and I have been with the Church since the dark days in Jackson County—that the authority that ordered a murder committed, was the only responsible party, that the man who did the killing was only an instrument, working by command of a superior, and hence could have no ill will against the person killed, but was only acting by authority and committed no wrong. In other words, if Brigham Young or any of his apostles, or any of the Priesthood, gave an order to a man, the act was the act of the one giving the order, and the man doing the act was only an instrument of the person commanding—just as much of an instrument as the knife that was used to cut the throat of the victim. This being the belief of all good Mormons, it is easily understood why the orders of the Priesthood were so blindly obeyed by the people.