Dateline | April 10, 2013
>> reporter: police investigating the home invasion murder of joe morrissey had to consider whether his wife, kay , had somehow been involved.
>> we conducted a comprehensive background investigation on kay . we went through all her phone records, who she's friends with, and to find out she maybe had a boyfriend or was dating somebody.
>> reporter: police found no evidence that kay had strayed in her marriage. what's more, they were finding plenty at the crime scene to support her story. the broken window screen, zip ties , and towels. kay 's story seemed to be holding up. christina had believed from the beginning that her mother was innocent, purely a victim. but what she didn't know was how brutal the murder was.
>> she didn't want us to know. i remember sitting in the funeral home and she was very firm. you know, she just kept saying, it's going to be a closed casket. no one's going to see him. i want everybody to remember him as the lively person that he was. and i knew then that it was -- it couldn't have been good.
>> reporter: and when i sat down with kay , she told a story filled with love and courage on that awful night.
>> you're surrounded by evil. my insides were shaking. i was just thinking about patrick .
>> reporter: and that was the theme of the story kay told me. how her 5-year-old son patrick was foremost on her and her husband's minds. that's why kay says she became especially panicked when she and joe were forced to go to the bank by the man with the gun.
>> i said we can't leave patrick by himself here. no, he stays, and he told us that there were people there and that they had guns.
>> and there you are getting in the car with your husband. and some guy with a gun. and leaving your 5-year-old at home. with --
>> we don't even know.
>> with we don't even know who that was.
>> it's just crazy. i mean, i just -- i'm crying hysterical.
>> reporter: in the car kay feared for her and joe 's lives as well. as they returned from the bank to their home, they heard a siren. kay thought help was on the way. they would be saved. the gunman thought this might be the end of him and of them.
>> when he heard the siren, he becomes very strange. he started singing and taunting us. they're coming for me, i'm going to kill you i was just so horrified.
>> reporter: but help did not arrive. once at home, when the gunman forced kay and joe back into the master bedroom , at least they found patrick , thankfully, still asleep. and in that moment, kay says, a father's love came shining through. that's when joe morrissey , tied up and helpless, made a move to save his young son's life.
>> patrick is now awake and he's now sitting on the bed. so joe says to him, " patrick , do it for daddy. please do it for daddy. just lay down and pretend you're asleep."
>> do it for daddy.
>> do it for daddy. and he just lays there and pretends to be asleep.
>> reporter: kay says the man with the gun forced joe to go to the other side of the house. in his final moments with his attackers, kay says family was first on joe 's mind.
>> he starts pleading, please, you know i have kids, please don't do it.
>> reporter: those would be joe morrissey 's last words. then kay saw an orange glow. their home was on fire. the attackers had fled, and now she had to get patrick and herself out of the house. but her ankles were still tied, and she could barely move. desperate to find something sharp to free her feet, kay hobbled to a nearby bathroom.
>> i took everything out of the drawers. i just created a humongous mess. but i couldn't find the scissors. so i called patrick , and i said to patrick , you have to be a big boy . you have to help mommy.
>> reporter: and he did. kay told him where to find a pair of scissors. and patrick brought them to her. cutting the zip tie was difficult, but kay was finally able to do it. the 5-year-old boy had saved his mother. then she had another job for her son.
>> so i said, " patrick , please, just go across the street, knock on that door. mommy's going to stay here. do it for mommy, please. i need to go help daddy. remember your karate moves. remember your kung fu kicks. please, just kick the door."
>> reporter: kay saw the neighbor's door open and patrick run in. she knew he was safe. one family member taken care of. now kay was on a mission to save joe . she would not leave him behind. no matter what the risk.
>> and then you run back into a burning house.
>> yes. i went back in there. and when i saw joe , it was so hard to pick him up. i remember seeing so many wounds, so much damage to his body. i couldn't even think anymore.
>> reporter: kay managed to drag joe out of the burning house and onto the patio. she held out hope that while joe was clearly badly injured he was still alive. paramedics arrived. but there was nothing they could do for joe morrissey . kay 's beloved husband was gone at the age of only 46.
>> and that was the last time i saw him.
>> you saved yourself. you saved your son.
>> but i didn't save joe . i just couldn't. it was the most horrible thing that ever happened to me, that learn that he was dead.
>> reporter: it was a heartbreaking story and one that police came to believe. they cleared kay .
>> we found no evidence that would support us to believe that she was involved in any way in this murder.
>> reporter: now it was up to investigators to find out who had done such horrifying things to this family. a family detective kendall believed that had been targeted. but so far it wasn't making any sense.
>> if it was just something personal in nature, why not just come in and kill them and leave?
>> reporter: the search for answers was on. and it would lead to a very different kind