very clear. >> there was a detective who said, whoever this print belongs to is definitely the killer. i'm thinking, god, definitely's a strong word. how do you know that? and then he said the way the knot was tied, you have to put your hand there to do it. >> in a surprising development, the print on the water heater matched dana's estranged husband, mike satterfield. the couple, who had two young children, were recently separated. >> all indications from the crime scene would be that the assailant knew dana. it was angry and personal and vicious and vindictive. >> did dana's husband have an alibi? when does your work end?