now, he was fully convinced nick holbert had killed kelli. y. >> how can i be his friend? and i had to do some things, say some crap that i just didn't believe. but i had to do it to play the part. >> reporter: marshburn bought holbert countless meals, beers, even hired him to do odd jobs. slowly, becoming a bff. or maybe, more of a frenemy. but marshburn said he paid a high price, as he practically abandoned his wife and young son. >> i didn't do any family stuff. if we were eating somewhere, and nick picked up the phone and called and said, hey, i need cigarettes, man. i need some money. i get up, and i'd leave. and i'd go straight to him and do what i had do and come back. >> were you obsessed? >> when i have somebody i'm hunting down, i don't stop till i get 'em. >> isn't that being obsessed? >> i don't know. dedicated. >> get the answers you need. >> i'm not going to stop until i do get the answer or the answer comes. >> reporter: but holbert, still, wasn't providing any answers about kelli. who had now been missing some-18 months. by thi