then a startling comment takes detective ken swift completely off guard. >> these two girls were huggingeach other, and when i said, you know, what can i do to make this easier for you? they turned and looked at me and they said, can we watch csi? the hairs on the back of my neck stood straight up. essentially, it was right then. it was like something was very, very off. >> and cops noticed something even more suspicious. >> they would cry a lot, but it was tearless crying when i would ask them to describe their mother. they were very insulting of their mother. >> during the interview, detectives observed the twins still wearing gloves. >> let me see your hands and your arms. >> what's going to happen here? okay. so fight if you get in a fight with her. >> as they weave their story back at the bloody crime scene, investigators uncovered physical evidence the saints were completely clean and white. >> we found shoes in back of their closet that had blood on it. >> and in taz bedroom, there's a pair of brown boots that have a significant amount of blood on them. >> i found a clump of hair.