It was ordered by the church's prophet and president, Brigham Young. Author Will Bagley implicates Young directly in the massacre. Bagley's book "Blood of the Prophets: Brigham Young and the Massacre at Mountain Meadows " has generated considerable controversy since it was first published in 2002-OCT. He concludes that Brigham Young knew that the attack was imminent and, according to legend, sent the message "Brethren, do your duty." Bagley provides some circumstantial evidence in support of this assertion.

During a two-year famine that ravaged Utah in the mid-1850s, Mormon leaders subjected the people of Utah to an orgy of religious fanaticism known as the “Reformation.” John M. Higbee, who gave the orders to kill the Arkansans at Mountain Meadows, recalled in 1896 that Cedar City was in the grip of “a craze of fanaticism, stronger than we would be willing now to admit.” Perhaps the most troubling aspect of the Reformation was the Mormon leadership’s obsession with blood and their public calls for murder. Their rhetoric dripped with sanguine imagery, and their Old Testament theology incorporated this dark fascination in a perplexing doctrine known as “Blood Atonement.” Joseph Smith taught that certain grievous sins put a sinner “beyond the reach of the atoning blood of Christ.” Their “only hope is to have their own blood shed to atone.” Strictly interpreted, the doctrine may have applied only to believing Mormons, but the words of its prophets suggest the LDS church shed the blood of apostates “as an atonement for their sins.”[5] As the doctrine evolved under Brigham Young, it would have a powerful-and confusing-influence. Of all the beliefs that laid the foundation of Utah’s culture of violence, none would have more devastating consequences.

If a Saint committed an unpardonable sin, Young asked early in 1857, “Will you love that man or woman well enough to shed their blood?” He knew hundreds of people who could have been saved “if their lives had been taken and their blood spilled on the ground as a smoking incense to the Almighty, but who are now angels to the devil.” If a man wanted salvation and it was “necessary to spill his blood on the earth in order that he might be saved, spill it … That is the way to love mankind.” It was strong doctrine to cut “people off from the earth,” he conceded, “but it is to save them, not to destroy them.” Sinners should welcome blood atonement and “beg of their brethren to shed their blood.”[6]

Young’s private statements exceeded even the violent language of his public sermons. “I want their cursed heads cut off that they may atone for their sins,” he told the Council of Fifty in March 1849.[7] His interpretation of blood atonement evoked the Saints’ vision of themselves as an Old Testament people, an identification so strong that the plans for the Salt Lake temple included an altar “to Offer Sacrifices.”[8] The gory details of blood atonement shock modern observers, but the common experience of butchering animals made them less repellent to a farming people.

The Saints had a “right to kill a sinner to save him, when he commits those crimes that can only be atoned for by shedding his blood,” Jedediah Grant insisted. At the beginning of the Reformation, Grant advised sinners to ask Brigham Young “to appoint a committee to attend to their case; and then let a place be selected, and let that committee shed their blood. We have those amongst us that are full of all manner of abominations, those who need to have their blood shed, for water will not do, their sins are of too deep a dye.”[9]

Modern Mormon authorities insist blood atonement was a “rhetorical device” and “has never been practiced by the Church at any time,” but historian Juanita Brooks concluded that in Utah Territory, blood atonement was “a literal and terrible reality. Brigham Young advocated and preached it without compromise.”[10] The appearance in 1859 of the decapitated remains of two Mormon women who had consorted with soldiers at Camp Floyd -documented in army sources and in the Church Historical Department journal-puts the lie to claims that is it impossible to prove blood atonement ever happened.

Unfortunately for the groups of families (which came to be called "the Fancher party"), a revered Mormon apostle (and the great-great grandfather of 2008 Republican presidential candidate Mitt Romney), Parley Pratt, was murdered in western Arkansas within two weeks of their departure. News of the Pratt murder, committed by a non-Mormon angered over Pratt's taking of his wife, soon reached Utah, and greatly inflamed local hostility toward non-Mormons. When further word reached Salt Lake in July 1857 that the army was headed its way, Utah became a place hungry for retribution.