reading my bible. it was a little bit after 7:00 when i saw that i had a call from him. reporter: from daron wyatt. mary knew he was scheduled to meet with the d.a. my first thought was he was going to tell me that the meeting was canceled. again. reporter: but that was not the message. not at all. he said, i m standing here in front of sam s house and we are making an arrest right now. reporter: they re making an arrest. yes. and you thought? and i got up and i think i screamed there at the mcdonald s. reporter: years before, daron wyatt had made a promise. now, he felt, he was keeping it. that had to feel pretty good. yeah, there were tears of joy this time. reporter: sam lopez was arrested and charged with cathy s murder, but he wasn t alone. just as prosecutors now believed he wasn t alone the night he stabbed cathy to death.
i would actually go into their office and talk to them and tell them see what they could do. reporter: you were a pest? i was a squeaky wheel. reporter: your mom was relentless with the police. yes, she was. i went with her a couple times to meet the the new chief that would come into the police department. we go in there. you know, we just want to let you know that we represent cathy torrez, and we have not forgotten, and we just want to make sure that her case is still being worked on. reporter: we have not forgotten and we want to make sure that you don t either. right, right. reporter: the city of placentia didn t forget. the community learning center was dedicated in cathy s name. the cathy torrez learning center. yes. reporter: you ve got to leave your mark on the world. and she did, huh? reporter: and a tree was planted in cathy s memory across the street. they planted it in a way where from my mom s kitchen, she could see the tree. reporter: sa
memory of what had happened, but she was able to tell everybody who she had been with that night. reporter: the person cathy had been with that night? sam lopez. when police asked sam about that night, he remembered something very specific. a hickey. on her neck? on her right here. covered up with her bra. you mean way down here on her shoulder? right here. right here. reporter: sam claimed it was no big deal. i didn t want to hit her up, like, tell her, hey, you know, who were you with last night? whatever. reporter: but that night, police records showed sam received two traffic citations, both while driving cathy s car. one was an open container ticket for drinking alcohol in a parking lot. the other for failing to stop at a stop sign. the cop who pulled sam over for not stopping said sam flew through the intersection, and when he approached the car, the cop said it looked as if sam and
started dating albert and sam had another girlfriend, too, they continued to see each other. and daron found evidence that in sam s mind, his relationship with cathy was far from casual. mary gave me a shoe box full of letters that were written between sam and cathy, and the content of these letters showed a very jealous guy. a guy who would get angry any time somebody flirted with cathy. reporter: sam didn t try to hide the fact that he was prone to jealousy. she knows, every time she mentions some guy s name, i get pissed off, okay? reporter: that led the detective to take a fresh look at those bizarre events the week before cathy disappeared when she came home impaired and then had her tires slashed. she never regained full memory of what had happened, but she was able to tell everybody who she had been with that night. reporter: the person cathy had been with that night? sam lopez.
fingerprint, why would they charge sam? were you surprised you didn t find sam s dna there? yes. reporter: he thought newer, better tests might find sam s dna, but it was too late for that. cathy s family had sold the car. the case against sam would have to be entirely circumstantial. murphy felt the key to that was somewhere in those interviews sam gave to police. but here, too, there was a problem. when you look at the interview, everything that sam lopez said seemed logical at the time. and everything seemed to make sense. reporter: picking apart those interviews would be critical. this is one of those cases where you have to look at the details. and it s truly one that you have to look at each detail in light of every other detail. reporter: and when you rearrange the letters of little tiny details, it spells larry montgomery. absolutely. reporter: larry montgomery.