reporter: if bill thought changing his story about going into the bedroom to check on diane made him look better, he was probably the only one. i have told you what really happened. which version are we supposed to believe? you haven t been truthful to us at this point. you see how this is going? uh-huh. you fail a polygraph. your dna is on her neck. his isn t. the mountain s starting to build. reporter: detectives thought it looked like a mountain of evidence against bill kyne. what would the evidence say about kevin? coming up his glasses were found at the bottom of the bed. could there be a mountain of evidence against kevin, too? i said, your blood was found on your mom s leg. what s your explanation for that? reporter: detectives thought that? reporter: detectives thought . oh, boy. carvana just doesn t seem to understand how the test drive works. they give their customers seven days. and if they don t like it, they give em their money back. wai
clean up kevin and dirty up bill, had worked as the jury got the case and began deliberations. your honor, the jury has indicated they ve reached a verdict. reporter: it took six hours. would you hand the verdict form to the deputy, please. the little time it takes them to get that verdict form from the jury box up to the judge, to the clerk to read feels like eternity. in the state of florida vs. kevin lee kyne, the charge of murder in the second degree, the defendant is found not guilty. reporter: not guilty. that was probably the best feeling i felt in ten years. you got your life back that day? i did. reporter: kevin s paternal grandmother, his biggest supporter, cried tears of joy. across the aisle, bill kyne muttered to himself. i was devastated. i couldn t believe it. sometimes, the bad guy wins. you reclaimed his life. you pulled him out of the abyss? yeah, yeah. good job. you, too. any lawyer that tells you they never lost a case never tried any
reporter: the fifth amendment prohibits double jeopardy so kevin can t face charges in this case again. but bill could. i would like the prosecutor to ask the sheriff s office to reinvestigate diane kyne s death. that s silly. i d love to be the defense attorney on that case. there s no way bill kyne would be convicted. because, not only does the evidence not show that, but the defense would be kevin did it. who is kevin kyne? who is this guy? kevin kyne is a name on paper. that man is not a kyne. and he is not my family. so where s justice for diane in all this? kevin did serve some time in prison. and i i don t believe that diane would even want him to serve life in prison for her murder. but in my mind, he should still be behind bars. reporter: but now, kevin s got a second chance at life. he says he s dedicating it to his mother. she s looking down, and she sees that i m maturing. and i am gonna be the man that she wanted me to be. reporter: so, in the end,
he drew up the papers and we had him legally evicted. you can do that? you can evict a child? he was 21 at the time. reporter: but diane loved her only child and couldn t cut the cord. she let him come home. the summer of 2010, however, was racing towards a showdown. tensions in the family were high. the kyne house was cramped with four extra people. bill s son and his family camping out on couches because of financial troubles. kevin wasn t making things any easier, obnoxious about sharing the household computer. he was the computer hog. that s all he ever wanted to do, was sit on the computer. it wasn t even his computer, but he would change the passwords and kick everybody off. reporter: kevin s mother was furious. she d stop talking directly to him, trying to avoid the persistent arguments. they re just talking via e-mails? completely. 30 feet across the house and they re communicating by e-mail? not even 30 feet at times. reporter: the last straw was kevin cu
shocked investigators. her husband and son both pointing fingers at each other. police knew one of them had to be spinning an incredible tale. what story would the evidence tell? here is dennis murphy with true lies. reporter: bill kyne knew he was a lucky man. the single dad with five kids was getting a second chance at love. she was the most wonderful lady i d ever met. reporter: he first set eyes on her at a nail salon, a business she ran with her twin sister. and they re standing in front of this big neon sign that says, nails. and i said, do you all do nails here? and they just looked at the sign and then looked at me and said, yeah. reporter: her name was diane. a vivacious blonde, with a ready smile. he saw diane through the window, so the next weekend i went to get my nails done. reporter: rebecca kyne is bill s youngest child. gave him an excuse to meet her. rebecca, you were being used as bait.