Robert has a real problem with the historical record when it clashes with his conspiracy beliefs. There is of course no "routine protocol" to blame lone nuts when a president is assassinated. Investigations are done and blame is assigned to groups or individuals.
The Lincoln assassination was the result of a conspiracy. The 1950 attempt to take the life of Harry Truman by Puerto Rican nationalists was a conspiracy.
The historical record and all subsequent investigations gives us no reason to doubt that lone individuals killed presidents James A. Garfield, William McKinley and John F. Kennedy. (And if we don't limit ourselves to presidential assassinations, we can add Huey Long, Harvey Milk, George Moscone, et al to the list of elected officials brought down by lone gunmen.)
The lone gunman is in fact a specter that haunts the American political and social landscape. Witness the recent case of Congresswoman Gabrielle Giffords. A lone gunman killed John Lennon and lone gunmen attempted to kill George Wallace and Ronald Reagan.
And it was not an "excuse" of the Warren Commission that the Kennedy family would not release the JFK autopsy photos and x-rays. It a historical fact documented in numerous books and other sources, a fact Robert could have easily discovered for himself if he could tear himself away from the scribblings of his beloved conspiracy authors.
It is also untrue that no one on the Commission looked at the photos or x-rays. Earl Warren and chief counsel J. Lee Rankin were allowed (by Robert Kennedy) to review them.
In any case, this is all academic at this point. The autopsy photos and x-rays have been released and reviewed by several panels of experts who have concluded they are consistent evidence of a head shot to the rear.
But in Robert's conspiracy world, the opinions of these experts must be discarded because of the confused, contradictory and, in some cases, confabulated, "testimony" of the Parkland Hospital witnesses, the majority of whom later admitted they were mistaken.