***When the most despised man in town is murdered on Main Street*** This could be categorized as Southern Gothic, but it’s also a gritty real-life drama and murder mystery. Unlike movies like, say, “Macon County Line,” which was falsely advertised as a true story in order to hype it, this one is actually based on a real-life happening, the 1981 execution of Ken Rex McElroy in Skidmore, Missouri, which is an isolated town located in the northwest section of the state, a two-hour drive north of Kansas City. The two big changes this movie makes are that the story is switched from the Midwest to…