Danites

In 1838, members of the Church of Jesus Christ of Latter-day Saints from Caldwell County, Missouri, founded a fraternal organization known as the Danites. Though it is believed that the Danites operated as a vigilante group during the Mormon War, historians disagree as to the exact nature and scope of the organization. Nevertheless, the Danites and their alleged atrocities have become part of Mormon folklore and were even featured in the first novel starring which fictional detective? Discuss

Source: The Free Dictionary