If the JFK murder was a conspiracy, then it was a good one. People talk and are eventually found out. The same goes for RFK. Nobody has been able to tie Sirhan to anyone else.

The King killing was likely a conspiracy. James Earl Ray was a thief, and didn't amount to much. Someone probably had to finance his escape to Canada, buy his fake passport and pay for his trip to England. He was way out of his depth to be acting alone. I think it was planned for him to be captured in UK. A guy with an accent like his stood out big time.