Dateline | November 07, 2013
>>> catherine novak's death had been a cold case for more than three years when out of nowhere, a witness came forward pointing a finger at catherine 's estranged husband paul . so who was this mystery witness? a woman from paul 's past. his ex-girlfriend, michelle .
>> michelle lafrance, who was the defendant's alibi in 2008 has now come forward and said paul was not home and that paul went to narrowsburg and that paul killed catherine .
>> what was that phone call like?
>> it was now time to get to work.
>> jim farrell was now the district attorney. he teamed up with the former d.a.
>> didn't it feel good that you had a break?
>> it's a break. again, i needed more information.
>> investigators sat lafrance down to hear her story.
>> let's start back in the beginning.
>> during a six-hour interview, michelle laid out what she claims was the true story of how paul killed catherine . she said he started plotting weeks before the murder.
>> he was researching things on the internet. he was going to color form her and leave her and burn the house down around her and she would die in the fire.
>> a week before the fire, she went to move his things out. and paul unlocked the basement doors.
>> he said would go up the next time we had the kids a week later, that way he can sneak into the house and she wouldn't know.
>> according to michelleh paul wasn't with her on the night of the murder. that alibi was a liement instead, she said he was a fellow paramedic named scott sherwood who drove him to narrows burst.
>> as far as i know, scott was left in the car and paul walked down to the house.
>> michelle said paul told her he went inside, set off the basement smoke alarm, hid behind the stairs and when catherine came down to investigate, he tried to knock her out with chloroform.
>> this was supposed to be quick and painless and, you know, she was supposed to be passed out before she knew what happened. but i guess he put it over her mouth and it didn't work. she was screaming and begging for her life.
>> through her tears, michelle filled out gruesome details of what paul said were catherine 's final words. she begged him to think of their children.
>> he told me that the only thing he said to her the entire time that he was fighting with her was i'm doing this for the kids. and he said that she had been wearing a sweatshirt and that he took the sweatshirt and wrapped it around her neck and held it until she stopped breathing.
>> then, michelle claims paul took a blowtorch from the garage and set the kitchen curtains on fire.
>> he waited for it to catch fire and i don't know how long he -- i don't think he ever told me exactly he sat there and watched.
>> michelle 's story was a stunning portrayal of her former boyfriend. if it was true, paul committed a vicious and calculated crime. michelle said paul told her he did it because catherine was a monster.
>> he had me convinced that catherine was the bad guy and he was the good parent and these kids are abused and miserable.
>> he did it for the kids.
>> we need to save the kids.
>> paul 's sister alana didn't believe a word of it. from the moment she heard a witness had come forward, she was convinced her brother was being set up.
>> kept saying, this is michelle . you got rid of her and now what happened?
>> i believe that's what it is.
>> paul 's girlfriend, kat, who got engaged to him in jail, also believed michelle 's story was suspicious.
>> he's innocent. absolutely, positively.
>> why are you so sure?
>> he's just not that kind of a
person: he's a caretaker. you know, it's like his job is a paramedic. defines him.
>> while paul had a squeaky clean record, michelle , his accuser had issues. a history of depression and alcohol abuse and she had waited years to come forward.
>> michelle lafrance has been described as a scorned ex-girlfriend, a woman looking for revenge. did all that go through your minds?
>> no. i don't believe that it did because after she leaves paul in january, february of 2011 , it's 14 months before she gets up the courage to come forward to the police to tell the police what she knows. fully expecting that she's going to be arrested.
>> do i need a lawyer?
>> as paul waited for his trial to start, he told us he wasn't worried.
>> there's really nothing that puts you at that crime. no eyewitnesses. do you think that works in your favor?
>> i think it's going to go rather well for me.