I've been reading along, but have only made a few comments. I've been on the phone with a friend, who's about the same age as you, and she has been really upset about this....we both have elementary school children, plus she also has a toddler.
If he is capable of tying up little girls and shooting them in the head, he's certainly capable of lying to anyone and everyone about why he wanted to do it.
I'm suggesting that in all likelihood, nothing DID happen twenty years ago. He made it up. This is a script he wrote for how he wants to be remembered. Don't give him the credit of believing him.