in a moment that haunts him to this day, curt knox heard the verdict in italian. two kids were innocent, and to have them say guilty, it was just devastating. it was literally devastating. you know, i mean, literally the people that were in the courtroom just kind of went -- [ gasps ] >> reporter: dust preston is a best-selling author that dreams up chilling murder plots in his writing shack on the cold coast of maine. 11 years ago he had an idea to write a chilling tale, but in a warmer location. >> i moved to italy to write a novel, and we rented a house in the tuscan hills just outside of florence. >> reporter: his research began with trying to learn about the italian justice system. teaming up with an old italian crime reporter named mario spezzi, he soon was intrigued about a serial killer italy had yet to catch. the monster of florence who killed eight couples from 1968 to 1985. then vanished. >> when you are a novelist, you are just making things up. this was real. >> preston would quickly abandon his work of fiction for the real thing and began to learn ho

. >>> joining me now, amanda knox's father, curt knox joins me from seattle. i appreciate you coming on. we've been talking about your daughter's trial. we're glad to be able to get you on the show today. we covered what happened in court there about this rudy guede who was supposed to say that your daughter was not involved in the murder of her roommate, but in fact he said exactly the opposite. first, your reaction to what happened in court. >> well, first of all, within court today, he actually was answering questions specific to other inmates suggesting he confided in him that amanda was not there. he did not testify specific to whether amanda was there at the crime scene. in fact, it was also talked about today when police were monitoring him on skype at the very beginning of this process, that the police asked him a specific question, and he actually said amanda was not there at the scene of the crime. >> but certainly this was not you and your wife and daughter had hoped would come out in court. you would hope he would say he knew for sure she was not t

just an hour after hearing his daughter's 26-year prison sentence, knox's father curt and her sister deanna were overwhelmed. >> i thi i think those of us who have family members, who have children, couldn't help what it was like that moment, standing in that courtroom tonight and hearing that word, guilty. >> i collapsed shaking. >> it's not what anyone wants to experience. it's terrible. >> reporter: knox has lived in an italian prison since her arrest nearly four years ago. as has her then-boyfriend, who was also convicted. for the past six months, a new panel of italian judges and jurors are hearing knox's appeal, which she hopes will overturn her conviction. and finally, today, a glimmer of hope for amanda and her family. two independent dna experts who have poured over key dna evidence in the case since february filed their 144-page review of the dna. crucial to knox's appeal. and their findings seem to support amanda's defense. the report states that dna traces on two key pieces of evidence were too tiny to be tested, and that proper procedures were not followed. the evidence