Blood atonement

In Mormonism, blood atonement is a controversial doctrine that taught that some crimes are so heinous that the atonement of Jesus does not apply. Instead, to atone for these sins the perpetrators should be killed in a way that would allow their blood to be shed upon the ground as a sacrificial offering.

The doctrine is no longer accepted by The Church of Jesus Christ of Latter-day Saints (LDS Church), but was significantly promoted during the Mormon Reformation, when Brigham Young governed the Utah Territory as a near-theocracy. Sins that Young and other members of his First Presidency mentioned as meriting blood atonement included miscegenation, apostasy, theft, murder, fornication, and adultery.

Young taught that the doctrine was ideally to be a voluntary choice by the sinner, and, when non-voluntary, should be carried out with love and compassion. Young considered it more charitable to sacrifice a life than to see them endure eternal torment in the afterlife. 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 in the territory and state of Utah allowing capital punishment by firing squad or decapitation. 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 or non-capital crimes like miscegenation. There is, however, 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.

...
Wikipedia