." >> the canterbury hill subdivision in paducah, kentucky, is a good place to raise kids. tidy homes kept up by neighbors living ordered lives. as the front porch lights went down on just another day, what happened one cold january night in the wee hours was especially alarming. orange flames were licking the tree tops. a roaring all-consuming fire was devouring one of the nice homes. >> it was awful. half of the house was gone. >> what would rise from those ashes was far more than the far marshal's investigation into cause. there would be a probe into the deepest roots of a treachery beyond most people's comprehension. >> that's not true. no way. >> what had they all missed? >> a monster, a liar, a cheater. >> he's destroyed my entire family. >> before it became charred rubble, the house was home to a longtime paducah couple, keith and julie griffith. church going, gomp pllf playingh school sweethearts, 36 years into a marriage that had produced two sons. the older -- >> they were very supportive parents. they were loving. they loved my kids. >> aaron took after his dad,