“I have one problem with this theory - well at least one. If this were true it would have been a very simple matter to make sure that the younger one was not taken alive. I was betting that he would be killed last night yet he wasn’t.”
Simple, the FBI needs to determine the extent of the double cross.
Actually the other problem with this theory is that it took so long to find the suspects. Compare and contrast to how quick Oswald was found - someone who indeed was known to the government. And who by the way didn’t live to tell the tale.