Yes, I have information that would shed light on the idea that Rome controlled the matters of life and death over those in provinces they controlled as a way to have the locals hold Rome up as the supreme authority the local puppet leaders they installed.
Now mind you, the local puppets did execute citizens, but money was always a great briber to appease the Roman governors, so Rome itself seldom interfered. After all, the religious leaders wanted to ambush and murder Paul. They would have had not his nephew warned the Roman Governor.
Plus years later they executed James. From what my investigation showed was that they did so at a time that Judea was between Pro-councils, thus there was a void of legal Roman authority for a period of time that the Religious leaders took advantage of.
However, the very act that states Rome removed the right of capital punishment is all that was needed to assure the prophecy would be fulfilled.
That is far from a rigorous proof, but it is probably satisfactory for the moment. Any reputable publisher would demand much more.