Missouri Executive Order 44 (eat your heart out, George) was signed by Lilburn Boggs on October 23, 1838, and ordered that Mormons in the state be “exterminated” or exiled. This destroyed Boggs’ political career, but the order wasn’t formally rescinded until 1976 as a goodwill gesture by Governor Kit Bond. Zombie laws and orders are a hell of a drug that I imagine keep lawyers up at night.
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.