vkC56XgZW jpg
(100.11 KB, 994x1483)
The Bad Seed (1956). When a young boy dies and an investigation is leading the authority nowhere, a mother who's daughter was in the same class as the murdered boy starts finding evidence that her own daughter may have had something to do with the murder of her peer.
There is also a new movie that came out in 2018, although I have not seen the newer version (yet).