Dark Night of the Scarecrow (1981)

In a small country town, developmentally-disabled Bubba Ritter has the mentality of a child and is the best friend of a young local girl. When the girl trespasses into the yard of a house and is attacked by a vicious dog, Bubba saves her but is wrongly accused of killing her by her mother. The postman, Otis P. Hazelrigg, who has a virulent hatred of Bubba, recruits three other vigilante friends of his and after tracking him to an empty cornfield (where he had been hiding in plain view disguised as a scarecrow) the four execute the unarmed Bubba. After learning that Bubba was in fact innocent of attacking the girl, Hazelrigg makes it look as though Bubba had intended to attack them. The four men are brought to trial, but are declared not guilty and are are immediately released. However, justice comes from beyond the grave, and after being mysteriously visited by the vision of a scarecrow, they are mysteriously killed one by one. leaving Hazelrigg (who is desperately trying to figure out who is behind the killings) to the very last.