this man decided, came to the conclusion, that archie mcfarland was in his way and needed to die. >> nse argued the evidence was thin. no blood, no murder weapon. no witnesses. and dna found under archie's finger nails, it had now been determined, did not match janos. >> even if everybody right away things that janos kulcsar is the killer, there has to be proof beyond a reasonable doubt. >>, of course, gary mcfarland had no doubt he killed archie. he told the jury about that awful december morning when he discovered his dad dead on the driveway and knew instantly who did it. >> i turned around, looked at my mom, and said i can't believe [bleep] you know exactly what. she goes, i'm so sorry. i'm so sorry. i can't believe he's do this. i'm so sorry son. she was just -- she went hysterical. she lost it. >> so difficult to reign in the emotion even all these years. listening to the evidence, that the man spot cleaned the pants, easier for him to listen to the prosecution to pick apart janos's alibis. and janos never took the stand, just listened as his argued those changing stories were s