I think we could've learned about Ray's past, his wife and the fact that it was hard from him to accept that she was getting married, in some other say. I mean, not in a full episode. I think it took time from another character.
I like to see Nick and Sara work together, with this new attitude of hers. They were always the youngest in the beginning and have kind of grown together. The case was very good and it sort of teaches parents a very good lesson. Nothing justifies murder, but in the case of the young girl, she had a need. She needed to be loved, to be cared of, to be supported and she only got that from the nannies and some women that came through her father's life. So when the one person that shows up, cares about her and then leaves because something her father did, she had to do something. She had to have that love back. And sadly, that's how she managed to get it. With murder.