"The Bad Seed"

Rhoda Penmark seems like your average, sweet eight-year-old girl. After her rival at school dies in mysterious circumstances at the school picnic, her mother starts to suspect that Rhoda was responsible.

The Bad Seed is a 1956 American psychological thriller film directed by Mervyn LeRoy and starring Nancy Kelly, Patty McCormack, Henry Jones and Eileen Heckart.