l.j. were one and the same. either way ferry seemed like their man. but the d.a. wanted more evidence before filing charges. derek johnson and chad carpenter thought the blood samples taken from daniel ferry's home would push the case over the finish line. you and derek have to think >> bloodwork came back, and it was negative for blood. >> reporter: not only were the samples not annie's blood, it wasn't even blood at all. a major blow to the investigation. didn't mean he's not good for the crime? >> it doesn't mean that he's not good for the crime. it just led us to believe that, okay, it didn't happen here, at the ferry residence. >> reporter: so ferry might be good for this thing, but boy, you're just not getting there? >> yeah. >> reporter: the only bright spot, daniel ferry wasn't getting out of jail. he was also being investigated for an unrelated kidnapping and assault case in a neighboring town. so he's on ice while you guys can develop your theories about his involvement in this thing? >> yeah. >> reporter: they continued to investigate ferry. months went by.