The murder mystery of my lifetime. If I knew the answer, I'd most likely be rich & famous. :p
Personally, I eliminate Russians/Cubans. Had to be an "inside" type job. I would go with the CIA or any American group/organization. Too much info had to be known for it to be pulled off by foreign groups IMHO. Although, Oswald was definitely a part of it, and may have shot at least a couple shots. Too coincidental that he gets blown away without recordings of his interviews, not to mention a trial along with so many other discrepencies.
TIS