role was helping the prime suspect javier s cousin sam lopez. tina montelongo, sam s then-wife and javier s friend, wasn t buying it. can you conceive of javier going through with a murder or being involved in it because of his loyalty to sam? no. i don t see that. if sam did it, would xavi help him just because they re close family? i don t see that. reporter: neither did the d.a. who decided there was not enough evidence to file charges. how do you tell mary bennett, we had javier, but we had to let him go ? it was extremely difficult. there was a lot of crying on both sides. reporter: daron knew exactly what releasing javier really meant. what walks out of the jail along with javier is any leverage you had to get him to name sam?
yeah, we found xavier s profile on her sock, on the back of her knee, and under her right armpit. did we tell you? no, we didn t tell you. how long had they known that? a couple of months, at least. and they, what, forgot to call? i think the examiner who had been doing it was waiting for additional results and didn t realize that she hadn t notified us. so the idea touch so the so the idea of touch dna paid off? it did. reporter: but not quite the way they had all hoped. unbelievable that you would get touch dna evidence back that long after the fact. right. but bad news, it doesn t have sam lopez s name on it. right. that s right. reporter: so the strongest physical evidence was still against xavier. but it was sam who had the motive, and he was the first one going on trial, even without a trace of his dna anywhere. it had taken 13 years to arrest sam lopez, it would take another
problems in the past with boyfriends. reporter: then there was the second interview the day cathy s body was found. detective wyatt studied that tape, too. there was one thing that was important that sam didn t display, that you would expect to see in a case like this. which is? emotion. he showed more emotion over the contents of the coke can. he picked it up when they left the room. and he s reading the coke can and ingredients and the number of calories. and then at one point, he puts that down and he picks up a baseball hat that he had been wearing and he sees some dirt on it and he brushes it off and he starts swearing about the fact that there s dirt on his hat. oh [ bleep ] but he never shows any emotion about the fact that his gal has been brutally murdered. no emotion whatsoever. and that s a big red flag. it s huge. reporter: daron went deeper into sam and cathy s relationship. there were a lot of things that brought them together. they had dated in high
named albert. his jealousy was triggered that night he saw her with another man. he gets, in his own words, pissed. what he did was slash cathy s tires. obviously, someone would have to be pretty angry with her to slash tires. if the tires were slashed, ladies and gentlemen, there s only one person who did it. murphy said sam s anger continued to build as cathy s attention turned to albert, the same when when sam asked her to elope. a proposal she told her sister tina she was going to reject on saturday. the day she was killed. so now it s not just a hickey, it s a denial of a proposal. and it s all because of another guy. the result the prosecutor said was an attack so savage, cathy stabbed more than 70 times, it could only be the work of a jealous lover. every one of those cuts meant
investigators in 1994 took blood, hair and fingerprint samples from xavier, 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 xavier lopez to the crime lab. reporter: daron sent xavier 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: xavier 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 xavier s. and the detective found there was something else another major piece of evidence investigors had initially overlooked. when you look at the crime scene photos in the trunk of the car, something jumped out at me.