Aaand I'm back c: 

I think it's going to be her husband. Like I said, there was a clue about the boat a few episodes back and tonight the creepy old lady was talking to the detective woman about what happened with her husband and the abuse and she was basically like, WOULD U KNOW IF IT WAS HAPPENING UNDER UR ROOF? And then she came home and bitched at her husband about not doing anything all day. If it was the guy they have in custody already then it would have been over.