this man decided, came to the conclusion that archie mcfarland was in his way and needed to die. >> thed, 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 thinks that janos kulcsar is the killer, there has to be proof beyond a reasonable doubt. >> of course, gary mcfarland had no doubt janos 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 who did it. she goes, i'm so sorry. i'm so sorry. i can't believe he'd do this. i'm so sorry, son. she was just -- she went hysterical. she lost it. >> so difficult to rein in the emotion even all these years. easier to listen to the prosecution present the evidence suggesting the man spot cleaned the knees of dirty pants to wash away just the blood. easier for him to listen to the prosecution pick apart janos'changing alibis. and janos never took the stand, just