where months later the detective noticed one detail that saved the cover up. >> i was looking at the license plate, i see it's not there. should be a california license plate, that kind of thing, it's gone. i also see there is one screw missing and one screw screwed back in halfway and that screw came back positive dna to john creech. >> reporter: bingo, the unassailable link to pull together all that evidence. phone records, chandy's testimony, the friends, the dna and it all condemned john creech. but a surprise was coming. for everyone. >> raise your right hand. coming up. >> i was scared for my life. >> reporter: a dramatic tale from the stand. >> he punched me, pulled me in by my sweater. put his hand up on my throat, choking me on my throat. >> who attacked who? who would the jury believe ? >> my skin was just crawling. >> when "dateline" continues.