Dateline | November 07, 2013
>>> novak's body was discovered among the blackened ruins of her big red house. the passage of time didn't make it any easier for her mother.
>> it's the thing that never happens to you. it always happens to someone else. doesn't happen to you. you don't lose a child like that. it's such a horrible way, fire.
>> catherine 's brother michael and his wife joanne had stopped asking questions, choosing instead to accept they might never know what really happened to her.
>> to take catherine 's perspective, she would look for the positive side, the good things and she would want us to move on. and that's what we tried do. we made our peace with it. and we went on living.
>> but as time went by in the little town of narrowsburg, dark suspicions were whispered from neighbor to neighbor and one name kept coming up. catherine 's estranged husband paul novak . her close friend, sue muller.
>> i was angry as time went on and i thought more and more about it and i thought that paul might somehow be involved.
>> as she looked back, she was particularly haunted by the way paul acted the day of catherine 's memorial service .
>> the whole congregation were sobbing so loud. i mean, pastor couldn't even finish her sermon. i went up to him and i hugged him. i kind of was struck by how he really showed no emotion after 11 years of marriage that she might have meant a little bit more to him that he might shed a tear. but i didn't see any.
>> but there was no evidence that paul had anything to do with catherine 's death. no dna or fingerprints at the crime scene, no witnesses. he had even passed a polygraph test. and he had an alibi for the morning of the fire. he was three hours away with his girlfriend michelle in their apartment on long island. paul continued to enjoy his new life in florida with his two children. working again as a paramedic and now dating a new woman he had fallen for quickly on match.com, kat del grasso.
>> we started texting and made a date. we went on a date. really, that was it.
>> it was instant?
>> what was the attraction?
>> it's hard to put your finger on something like that. we seemed to have an immediate connection. there was zero stress talking, no uncomfortableness.
>> their romance blossomed and she eventually moved in with paul and his kids.
>> do they look up to him?
>> they worship him. they completely worship him. he's always up with them, checking homework. we do a lot of things as a family.
>> is it a nice life?
>> uh-huh. we were really happy. really, really happy.
>> and then you get a knock at the door.
>> yep. yeah. that was a tough day.
>> it was an early morning in september 2012 . four years after catherine 's death.
>> i was asleep. i was -- i just got off of work, i worked 12 hours at the hospital and i remember my girlfriend comes in and she goes there's something fishy going on outside. there's two police detectives outside and want to talk about your car being involved in a hit and run .
>> when he arrived at the police station , he saw a familiar face and realized this had nothing to do with a car accident .
>> this is investigator kelly from new york. i'm like, okay. so he sits down and he grabs a chair and he's like a foot away from me. then i remember him. he's the guy that grilled me, got in my face.
>> how are you feeling? oh, my gosh, these people are back in my life. four years later.
>> at that point i still didn't know what they wanted from me. i knew this guy was yelling at me. i looked at him and i said i would like to speak to a lawyer.
>> paul had already been interviewed by police several times. he thought this was all behind him.
>> you knew it had to be about catherine ?
>> well, obviously it had to be something with that.
>> later that day, the police went back to paul 's house.
>> i went outside in the driveway with them and they said we're sorry to have to break this to you, but paul novak is under arrest. i said for what? they said, for involvement in his wife's murder four years ago.
>> what kat and paul didn't know was that a witness had come forward telling police an evil tale and in that story, paul was the villain.
>> they arrested you --
>> right there.
>> did they put you in jail right there then?
>> the story they told was chilling. revealing dark secrets, but was it true?