and i was like, i pushed myself out this way, got out the driver s side. reporter: creech burst in like a machine, said chandy, started slugging, wouldn t quit. i was like, stop it, you re going to kill him. i was like screaming my head off. he comes out of the car and he goes, you re next and then i drove off. reporter: she was terrified, he said, afraid he d kill her, too, or tell the cops she set the whole thing up. so, did she? again and again the detectives listened to the under cover tape. i believe 100% that she did not know that was going to happen and she did not set it up. reporter: but they wondered, did she help cover it up? it s a serious business covering for a crime that awful. but chandy had a card to play. she agreed to testify. members and alternate members of the jury reporter: and in june, 2017, john creech went on trial. on the face of it, it looked
reporter: once chandy felt safe, she spilled it. all of it. how she and gavin met in secret at that secluded cul-de-sac, got close in gavin s car. and then all of a sudden the door opened, and johnny just goes and i just like pushed myself out this way. got out the driver s side. reporter: creech burst in like a machine, said chandy. started slugging, wouldn t quit. and i was like, stop it, you re going to kill him i was like screaming my head off. and then he comes out of the car and he s like, you re next. and then i drove off. reporter: she was terrified, she said. afraid he d kill her too or tell the cops she set the whole thing up. so did she? again and again the detectives listened to the undercover tape. i believe 100% that she did not know that was going to happen, and she did not set it up. reporter: but, they wondered, did she help cover it up?
powerhouse gym was very gossipy. so if you told the wrong person something, your secret would be all over the gym. reporter: lauren, just 18 years old back then, asked us not to use her last name. not after she found herself in the middle of a homicide investigation when police came across her while doing surveillance on john creech. lauren used to work at the pro shop of the powerhouse gym in chatsworth, california. and that s where she first met creech. he was beautiful. he was tall, and he was muscular. and a lot of women especially wanted to date him, a lot of men wanted to be him. reporter: lauren fell for him. he told her he was separated from his wife chandy, but that didn t stop chandy from calling lauren. she texted and called me and was very belligerent and rude. reporter: angry, perhaps, that her husband, then 39, was
reporter: once chandy felt safe, she spilled it. all of it. how she and gavin met in secret at that secluded cul-de-sac, got close in gavin s car. and then all of a sudden the door opened, and johnny just goes like and i just like pushed myself out this way. got out the driver s side. reporter: creech burst in like a machine, said chandy. started slugging, wouldn t quit. and i was like, stop it, you re going to kill him i was like screaming my head off. and then he comes out of the car and he s like, you re next. and then i drove off. reporter: she was terrified, she said. afraid he d kill her too or tell the cops she set the whole thing up. so, did she? again and again the detectives listened to the undercover tape. i believe 100% that she did not know that was going to happen, and she did not set it up.
reporter: but that afternoon lisa smith knew instantly, something must be wrong. her husband gavin was a dedicated father. nothing that would keep him from picking up his kid ever. reporter: because gavin was so good at these things, said his sister tara addeo, he was so impressive, so tall. you both got the tall gene, right? we did. whole family. whole family. reporter: gavin was the tallest, 6 6. he walked in a room, you noticed him. you wanted to gravitate to him. he was a magnet. reporter: he played basketball for legendary coach john wooden, ucla, 1975. he was a forward. it was wooden s final championship team. just to be on that team was pretty fantastic. it was a once in a lifetime. reporter: and then he drifted a bit. worked as a golf caddie and this