A cartoonish and crudely staged dramatization of a disturbing true crime.

The film owes whatever persuasiveness it has to the teen leads' sharp performances - their sisterly chemistry and their filial friction with an alcohol-addled mother, well played by Mira Sorvino.

Ms. Breslin and especially Ms. Henley are quite good, elevating a film that seems like an oft-told tale.

Every now and then, the film hits a definite note of ingenuity, but the deliberately quirky asides, which attempt to enliven the material, feel amateurish and false.