My idea is that this guy was recruited to do some covert thinggns for some mercenarys or some entity for years, which could explain his money. And he was gambler, the entire thing was setup and he was the fall guy. I could see where whatever group plotted this massacre had the idea to take advantage of some retiree and use him and manipulate him.
Im not trying to defend any of this, just doesnt add up, it takes skill and preparation to execute an operation of this magnitude. Its not as easy as it looks folks.
Sorry but you dont just covertly become a skilled operator of such complex tools and plot a massacre easily. Its hard to hide these days.
Bless the families who are affected.