In 1838, while living in Far West, Missouri and serving in the church's High Council there, Avard witnessed the heated conflict between the growing Mormon population and the established non-Mormon Missourians. He was the organizer and leader the Danites, a secret vigilante militia, bound by oaths and intent on retaliating for Mormon injuries and losses. It remains unclear the extent to which Joseph Smith was aware or in favor of Avard's activities, although he recognized the Danites and encouraged them to be lawful. Danite militaristic activities intensified the 1838 Mormon War and drew the attention of state government and militia.
After the Mormons were expelled from the Missouri and Joseph Smith was arrested, Avard was the chief witness against Smith, testifying that Smith was the mastermind behind the Danites. Smith denounced the group as "frauds and secret abominations" and excommunicated Avard in March 1839. Avard never attempted to return to the Latter Day Saints. By 1850 he was practicing medicine in Edwardsville, Illinois, where he died in 1869.