That's exactly the theory I had arrived at--he killed her in the throes of wild anger.
But that wouldn't explain the license plate, unless he did that later?
To me it seems the license plate + Hartford drive were planned. He probably thought no one would connect him to an area bellow his socio-economic status.
I think he planned this. I think whoever said he chose Memorial day weekend was right, thinking he'd get to keep the kids later on. He probably thought he'd get instant access to the money too.
He may be educated, but he seems dumb. In the sense that he's so in love with himself, so narcissistic, he has a different kind of logic. He might've thought "well they'll have to give me access to money, I have 5 kids to feed!" while completely ignoring the procedures that go into it - giving someone access to a trust fund, etc.
I think his attack was wild and full of anger, but it was a build up of anger, he has probably been thinking about it for a while. Guys like him use people and drop them when they are no longer needed... but in this case he locked her in with 5 kids, so she wasn't going anywhere and I'm sure he tried to constantly control her through them.
I hope grandma gets full custody. Their father does not care about them or anyone. I'm sure he'll try to blame MT for some stuff too.
----
Also, this is my first post, hello to everyone. I've been reading WS on and off for years, but this story really pulled me in so I decided to make an account.