him. >> i showed him certain excerpts out of juliet driscoll's statement.put his head on the table and said i'm [ bleep ]. but did that mean he was guilty? or merely that he understood the police believed he was guilty? >> he made comments like, there is no magical way i can tell you where to go to find the truth. >> reporter: christopher sutton and garrett kopp were charged with first degree murder, possible death penalty case, both pleaded not guilty. and john sutton got busy. he had a mission, two, in fact. one to seek justice no matter what that might mean for his son. and the other, perhaps even more impossible, to simply see again. coming up, garrett kopp's confession should be enough to put him behind bars. but did prosecutors have enough to convict christopher sutton? >> this was a circumstantial case, extremely circumstantial. really based on motive. >> reporter: when "dateline" continues. you probably aren't going to brush your teeth as effectivity because it causes pain. and if you see blood you should do something about it. you know, i talk to d