I think that it is pretty clear that Pattons death will go unpunished regardless of the results of any investigation.
As this article points out the driver of the truck is already dead. Those who ordered the assassination undoubtedly would be even older than the driver ensuring that they also are already dead.
Yes certainly Pattons death should be investigated but the opportunity for punishment is long gone.
If the conspiracy theories were proved correct, then SOMEBODY must be punished. I nominate La Raza. Wipe 'em out.
Makes as much sense as punishing all of us financially today for the sins of slavery perpetrated by the people who lived 150 to 400 years ago.