Early on I resisted the idea that she had threatened to leave him and that he saw the future of alimony and child support payments etc. in a blinding flash and decided to get her out of the way. But I think your right. She threatened to divorce him and he killed her. But to me this suggest a degree of premeditation. I suspect the cops see it that way too!
He strikes me as a spoiled brat who got pretty much whatever he wanted as a child and couldn't relinquish that role as an adult. The Country Club membership, the gourmet dining bit, the "extravagance" of "keeping" other women. I guess he saw his future as being hell and she was going to be the cause of it and he just couldn't allow that to happen.
You have to be one very callous and manipulative individual to leak fake tears on TV knowing that you "dumped" the bodies of your wife and baby into a watery grave where you're sure her family will never find her!
When I read on another forum that he's the youngest in a family of 7 children, his behavior has struck me as that of a spoiled brat too, going through life always being bailed out by his parents.
No, I'm not saying the baby of the family is always a brat! But I can see how birth position can sometimes lead to such behavior.