samples from javier, they'd never had those tested. >> they had sent all of the evidence related to sam lopez to the crime lab, his fingerprints, his hair, his blood. but they hadn't sent anything related to javier lopez to the crime lab. >> reporter: daron sent javier's samples, now three years old, to the crime lab. two months later, the phone rang. >> they had positively identified a fingerprint on the trunk of cathy's car, left there by somebody closing the lid of the trunk. >> reporter: javier's print was on the trunk of cathy's car? >> yes. >> reporter: weeks later, another call from the lab. a bloodstain on the car had tested positive for both cathy's dna and javier's. and the detective found there was something else -- another major piece of evidence investigators had initially overlooked. >> when you look at the crime scene photos in the trunk of the car, something jumped out at me.