“How does one make money over any long period of time playing video poker machines? “
You don’t. As you point out these things are carefully calculated to make money for the house.
But a criminal who needs to explain large amounts of money can make it appear legit by claiming to be a successful gambler.
The shooter and his brothers were with their dad when he was living the life of a career criminal. They learned his methods for getting money and concealing it. And they improved upon them enough so that their cover story is still holding up. The only flaw being that big brother had the crazy gene in spades and if there are some diligent and curious investigators who start looking into the killer’s finances the whole thing will unravel.
It appears one way to make money as a professional video poker player is to sell books and videos teaching people how to become a professional video poker player.
https://www.youtube.com/watch?v=oV-DBdT14aw
that would be the logical explanation for what is going on. His father being a master criminal on the wild side. So what his son does after successfully concealing who he really was for all these years now makes sense.
My bigger question is did he work alone? If not with whom.I could guess but hate doing so.