Who was the killer in baby its you part 2?

At first they look at the son of the baby sitter, but he is exonerated and later is a witness for the prosecution because he saw the assault .

Eventually the father is prosecuted but after the district attorney rests his case, the defense reveals that he was with a mistress at a hotel at the time of the assault.

The investigators then turn their attention to the mother, Mrs. Janaway. Mr Janaway admits that his wife as been assaulting the girl for some time. She later confessed she was jealous of all the attention her daughter was getting particularly from her father and assaulted her because of it.