Ex-Mormon here. There was an urban legend that went around my community for years about some dude who got into an argument with a neighbor, and killed him. His lawyer got him off on the charges, arguing that the Extermination Order was still in effect, so murdering his neighbor was perfectly legal. The other versions I heard were a serial killer who only targeted Mormons because he could get away with it, and organ harvesters who were kidnappings Mormon missionaries in Missouri to steal their kidneys… it’s a long list of bs that probably started as speculation, and it evolved into narrative, and then it evolved into an urban legend.