A brother and sister live with their mother, they are disgustingly rich, and the son accidentally shoots the mother, they have a servant in the house, a gardener who needs to avoid probation, the sister sleeps with him.. .and then he tries to accuse her of
that he killed their mother……..
I don’t know the name, but it reminds me of a movie that starred Sarah Michelle Geller that played a very rich girl who was having a love affair with her brother and I believe they killed one or both parents.