I don't think it was either of the suspects they had in mind. I think it was someone else and I also think he had more than the 3 victims. There was a short stretch between Wanda and Michelle. Makes me wonder if there is at least 1 more victim between Carla and Wanda. Then the murders stopped. Usually that means incarceration or incapacitation of some kind. This kind of killer isn't the kind to just stop. He would escalate.