The CIA, who at that point in time were very off the leash, because of the Bay of Pigs massacre, worked the hit through their contacts in the Dallas mob. Kansas City, the seat of mob power in the US, signed off on the cooperation likely due to Bobby's crusade to destroy their business ventures. Corrupt local law enforcement helped to launder the physical evidence so that what was presented to the public would pass a sniff test. The scale of the crime however necessitated a full blown Federal investigation which got us the suspect findings of the Warren Commission and the House Select Committee and the continuing public distrust in the confirmations of those committees.
Senior year history elective was a class called Crime and Violence that everyone took and Rush to Judgement was one of the books we were assigned to read. I can't help it, they got me early on this one. I've also been to Dealey Plaza but this would have been in the early 90s and nothing was marked. It was just another piece of Dallas landscape.