thumb|250px|right|[[Execution by firing squad of John D. Lee for his role in the Mountain Meadows massacre. Lee's blood was shed on the ground where the massacre had taken place 20 years earlier; nevertheless, Brigham Young said that Lee "has not half atoned for his great crime."]]
Blood atonement was a practice in the history of Mormonism still adhered to by some fundamentalist splinter groups, under which the atonement of Jesus does not redeem an eternal sin. To atone for an eternal sin, the sinner should be killed in a way that allows their blood to be shed upon the ground as a sacrificial offering, so they do not become a son of perdition. The largest Mormon denomination, the Church of Jesus Christ of Latter-day Saints (LDS Church), has denied the validity of the doctrine since 1889 with early church leaders referring to it as a "fiction" and later church leaders referring to it as a "theoretical principle" that had never been implemented in the LDS Church.
The doctrine arose among early Mormon leaders and it was significantly promoted during the Mormon Reformation, when Brigham Young governed the Utah Territory as a near-theocracy. According to Young and other members of his First Presidency, eternal sins that needed blood atonements included apostasy, theft, fornication and adultery (sodomy was one sin that did not need blood atonements).
Young taught that sinners should voluntarily choose to practice the doctrine but he also taught that it should only be enforced by a complete theocracy (a form of government which has not existed in modern times). Young considered it more charitable to sacrifice a life than to see them endure eternal torment in the afterlife. In Young's view, in a full Mormon theocracy, the practice would be implemented by the state as a penal measure.
The blood atonement doctrine was the impetus behind laws that allowed capital punishment to be administered by firing squad or decapitation in both the territory and the state of Utah. Though people in Utah were executed by firing squad for capital crimes under the assumption that this would aid their salvation, there is no clear evidence that Young or other top theocratic Mormon leaders enforced blood atonement for apostasy. There is some evidence that the doctrine was enforced a few times at the local church level without regard to secular judicial procedure. The rhetoric of blood atonement may have contributed to a culture of violence leading to the Mountain Meadows massacre.
Blood atonement remains an important doctrine within Mormon fundamentalism and is often referenced by alt-right Mormon groups (such as the DezNat community online). Nonetheless, the LDS Church has formally repudiated the doctrine multiple times since the days of Young. LDS apostle Bruce R. McConkie, speaking on behalf of church leadership, wrote in 1978 that while he still believed that certain sins are beyond the atoning power of the blood of Christ, the doctrine of blood atonement is only applicable in a theocracy, like that during the time of Moses. In 1994, when the defense in the trial of James Edward Wood alleged that a local church leader had "talked to Wood about shedding his own blood", the LDS First Presidency submitted a document to the court that denied the church's acceptance and practice of such a doctrine, and included the 1978 repudiation. Arthur Gary Bishop, a convicted serial killer, was told by a top church leader that "blood atonement ended with the crucifixion of Jesus Christ."
The concept of blood atonement for adultery was less clearly articulated in LDS scripture. In Doctrine and Covenants 132, Joseph Smith wrote that people who break the "New and Everlasting Covenant" (Celestial marriage) would be "destroyed in the flesh" and be punished until they received their exaltation at the Last Judgment.
The requirement that blood should be shed as an atonement for capital crimes grew into the idea that salvation would be blocked unless this penalty was adhered to, because the "law" would remain "unfulfilled." The belief in the necessity of spilled blood and death in order to make restitution for adultery and murder was aided by a generally favorable view of capital punishment, the idea that spilled blood "cries out" for retribution, the "blood for blood" doctrine that says crimes of bloodshed should be punished by the spilling of blood, and the concept that repentance requires restitution. Although the scriptures in Alma 34 of the Book of Mormon speak of the "requirement" in terms of a legal obligation, Brigham Young described blood atonement-worthy crimes as precluding Eternal Progression offered to the faithful, stating that a sinner's crimes "will deprive him of that exaltation which he desires." In Mormon theology, Salvation is not the same as Exaltation, which has more to do with "where in heaven" whereas Salvation is "being in heaven."
Capital punishment in Mormon scripture and ritual
Mormonism's teachings regarding capital punishment originated in older Jewish and Christian teachings. The Doctrine & Covenants also has passages favoring capital punishment, saying "And now, behold, I speak unto the church. Thou shalt not kill; and he that kills shall not have forgiveness in this world, nor in the world to come. And again, I say, thou shalt not kill; but he that killeth shall die." Elsewhere, though, people are portrayed as having been forgiven for murders.
Underlying the blood atonement concept is the idea that spilled blood "cries out" for retribution, an idea that is advocated in several passages of Mormon scripture. In the Bible, the blood of Abel ascended to the ears of God after he was killed by Cain. In the Book of Mormon, the "blood of a righteous man" (Gideon) was said to "come upon" the theocratic leader Alma "for vengeance" against the murderer (Nehor). Mormon scripture also refers to the "cry" of the blood of the saints ascending from the ground up to the ears of God as a testimony against those who killed them. After the death of Joseph Smith, Brigham Young added an Oath of Vengeance to the Nauvoo Endowment ritual. Participants in the ritual made an oath to pray that God would "avenge the blood of the prophets on this nation." The prophet was Smith and "this nation" was the United States.
Temple penalties
Before 1990, the LDS temple rituals provided examples in which violent penalties are contemplated instead of violating covenants made in the Endowment ritual. These penalties were intended to protect the ritual's secrecy. In keeping with the idea that grievous crimes must be answered with bloodshed and that blood atonement should be voluntary, participants made an oath that rather than ever revealing the secret gestures of the ceremony, they would rather let "my throat ... be cut from ear to ear, and my tongue torn out by its roots"; "our breasts ... be torn open, our hearts and vitals torn out and given to the birds of the air and the beasts of the field"; "your body ... be cut asunder and all your bowels gush out." The gory wording was removed early in the 20th century and changed to a less explicit reference to "different ways in which life may be taken." Vestigial accompanying suggestive gestures were removed by the LDS Church in 1990. Author Peter Levenda linked Smith's introduction of the Masonic blood oaths into the temple endowment as a step towards later threats of blood atonement for other perceived crimes in Utah territory. Historian Wallace Stegner wrote "It would be bad history to pretend that there were no holy murders in Utah and ... no mysterious disappearances of apostates". Another historian Juanita Brooks stated that violent enforcement of religious oaths was a "literal and terrible reality" advocated by Brigham Young "without compromise". One example cited by historians is in March 1857 when an elderly church member of high standing William R. Parrish decided to leave Utah with his family when he "grew cold in the faith", but had his throat slit near his Springville, Utah home.
"Blood for blood" doctrine and retributive capital punishment
thumb|200px|right|[[Joseph Smith did not teach blood atonement, but taught a "blood for blood" law of God's retribution, stating that if he could enact a death penalty law, "I am opposed to hanging, even if a man kill another, I will shoot him, or cut off his head, spill his blood on the ground and let the smoke ascend thereof up to God..."]]
Joseph Smith, the founder of the Latter Day Saint movement, was a strong proponent of capital punishment, and favored execution methods that involved the shedding of blood as retribution for crimes of bloodshed. In 1843, he or his scribe commented that the common execution method in Christian nations was hanging, "instead of blood for blood according to the law of heaven." Years before making this remark, however, Smith was quoted as saying that the hanging of Judas Iscariot was not a suicide, but an execution carried out by Saint Peter. In a March 4, 1843, debate with church leader George A. Smith, who argued against capital punishment,