reporter: and in this case, they called in sheriff detectives ty labbe and his partner john o brien. his phone was missing. there was no use of it. we checked his bank accounts from the time that he was missing. we checked his medical insurance to see if he had checked himself into a hospital. that never showed any activity. he was completely dropped off the face of the earth. reporter: but then, out of nowhere, a sighting. hundreds of miles north of los angeles, a businessman visiting california s central coast said he saw gavin smith and a beautiful woman at a cash-only taco restaurant in morro bay. i happened to click on the link, saw the photo, and i said, oh, boy! reporter: the waitress corroborated the story. he was sitting here, she was sitting right here. reporter: gavin s sister tara raced up the coast to the restaurant. and i said, here s my brother s picture. did you see him? and? no. that was truly heartbreaking to
reporter: he went to a drug rehab center called the matrix institute here in the san fernando valley. he clearly stopped using. he was feeling healthier than he had felt in years. reporter: but when detectives john o brien and ty labbe learned about gavin s addiction, they had to consider a raft of new possibilities. he disappeared. maybe he overdosed. we didn t exactly have any of those answers. driving all over the valley, we would have moments in the car of where we looked at each other and said, i think this is a suicide. and then an hour later, we d interview somebody or something would happen, and we d go, i think this is a murder. and our feelings and our gut instincts were going different ways very early on very fast. yeah. it s got to be pretty unusual though? it was very confusing. reporter: confusing for lisa too, because here was another secret, the smiths were underwater on their mortgage.
welcome back. nearly three years after gavin smith s disappearance, john creech was charged with his murder. police believe john carried out the rage-fueled killing as revenge for gavin s affair with john s wife chandy. several of john s associates admitted they helped john hide evidence. but investigators did not think they had the whole story just yet. and there was one person who could give it to them directly. so they figured out a way to get it. once again, here s keith morrison. reporter: detectives john o brien and ty labbe had a problem. an important witness who wouldn t talk. chandrika creech had clammed up. but there s more than one way to get a story. they found an associate of john creech s, someone who knew chandy. they convinced him to wear a wire and meet with her. it worked. do you want the whole story? yeah.
he was prescribed oxycontin, and he was addicted to it. reporter: he went to a drug rehab center called the matrix institute here in the san fernando valley. he clearly stopped using. he was feeling healthier than he had felt in years. reporter: but when detectives john o brien and ty labbe learned about gavin s addiction, they had to consider a raft of new possibilities. he disappeared. maybe he overdosed. we didn t exactly have any of those answers. driving all over the valley, we would have moments in the car of where we looked at each other and said, i think this is a suicide. and then an hour later, we d interview somebody or something would happen, and we d go, i think this is a murder. and our feelings and our gut instincts were going different ways very early on very fast. yeah. it s got to be pretty unusual though? it was very confusing. reporter: confusing for lisa, too, because here was another secret, the smiths were
reporter: and in this case, they called in sheriff detectives ty labbe and his partner john o brien. his phone was missing. there was no use of it. we checked his bank accounts from the time that he was missing. we checked his medical insurance to see if he had checked himself into a hospital. that never showed any activity. he was completely dropped off the face of the earth. reporter: but then, out of nowhere, a sighting. hundreds of miles north of los angeles, a businessman visiting california s central coast said he saw gavin smith and a beautiful woman at a cash-only taco restaurant in morro bay. i happened to click on the link, saw the photo, and i said, oh, boy! reporter: the waitress corroborated the story. he was sitting here, she was sitting right here. reporter: gavin s sister tara raced up the coast to the restaurant. and i said, here s my brother s picture. did you see him? and? no.