The horror of LeRoy’s The Bad Seed is serial killer Rhoda Penmark, a darling little girl with blond pigtails and blue eyes who murders a classmate at a school picnic because she covets his penmanship medal (pun intended). The picnic food is present but inconsequential.
As in March’s novel, the picnic serves as an unsettling setting for murder. It’s the first of Rhoda’s murders that identifies her as a successful serial killer.
Wanting the medal for herself, Rhoda follows her schoolmate Claude around, trying to snatch it. When that fails, she lures Claude to a pier on the Little Lost River (another pun). When his body is found with bruises on the forehead and hands, it is assumed these are accidental. But when the medal is not found, there is suspicion that Rhoda is somehow involved. Lacking anything but circumstantial evidence, Rhoda’s mother Christine suggests, “So many things could have happened quite innocently.”
A force of Nature serves justice. Leroy’s film character follows March’s narrative: Rhoda murders Claude and is unpunished. However, because the screenplay was subject to the censorship guidelines of the Hollywood Motion Picture Production Code, murder required punishment even if the culprit was a girl of twelve. To appease the Code criticism, LeRoy and screenwriter John Lee Mahin resorted to the realm of improbability by having Rhoda return to the picnic grounds during a severe thunderstorm. She’s hellbent on retrieving the medal from the water when a lightning bolt blows her to smithereens. 
Featured Image: Patty McCormack as Rhoda Penmark at the school picnic
See William March. The Bad Seed. New York: Rinehart & Company, 1954; Maxwell Anderson. The Bad Seed, the Dramatization of William March’s Novel. New York: 1954; Mervyn LeRoy. The Bad Seed (1956). The screenplay by James Lee Mahin is based on March’s novel and Maxwell Anderson’s play. There are two subsequent films: Paul Wendkos’ 1985 and Rob Lowe’s 2018