slamming doors, things like that but just -- just arguing about anything, nothing. >> we never really thought too much about it. >> reporter: anyway, now it was that calamitous christmas eve, 2006. as always, there had been a happy dinner celebration with brad's side of the family. >> christmas eve, we would go to my grandma's there in town. >> reporter: and then, back home, games, and stocking stuffing, and of course -- >> wake up real early and open all the presents. >> reporter: lisa had no idea that brad had bought her a $3,500 diamond ring, got the kids to help him pick it out. back from grandma's, he waited for his chance to hide it in her stocking, but -- lisa kept fiddling on the computer and the kids were playing a board game. >> i think it was monopoly. >> we just played downstairs for awhile and then eventually went up to our rooms. >> reporter: it was well after midnight when they heard the raised voices downstairs.