I think he killed Denise before he left. Just a hunch, but I think he killed her and had to flee. I also think Denise Beaudin and Donna Laporte are the same person, I think he changed his name and her name, just like he changed Dawn's name to Lisa. My guess is, it's been so long for Lisa that she most likely doesn't remember much from those early days, which might be a blessing considering what may have been going on. It's possible BE was incarcerated during the years before 1977, or that he was in the armed forces. Seems like someone would have remembered him from school or something, unless he was from outside the country? Just covering all the bases. His biological child does look Alaskan, maybe he was from up that way? He might have other children too, but just took her and killed the rest of his family. Wish we had some front on pics of him from when he was younger, the pic at the party he's turned away so it's hard to see his face.