At the risk of seeming uninformed, I don’t recall ever having heard of John T. Orr before his name surfaced in connection with the Knott Lab animation “disproving” the SBT. I learned he had been with the Justice Department as an antitrust attorney and had been on an anti-SBT crusade since 1995. Since no one can locate the Knott "study," if there is one, I did a search for any research Orr might have published.
This is his exceedingly well-illustrated and well-argued 66-page analysis of what occurred:
http://www.mountainrivercabins.com/JohnOrrReport.pdf. It appears, weirdly, at the site of “Mountain River Cabins,” a development in Georgia that Orr apparently owns. I don’t know when this analysis was published or that it represents Orr’s current thinking, but I assume it’s close.
Orr posits four shots: Oswald hits JFK in the back at Z204, the bullet exits the throat at a slight upward angle and dents the windshield. 1.75 seconds later, Z236, Oswald shoots Connally in the back, and this is CE 399 but not what caused JBC's wrist injuries. The third shot, the kill shot to the head, was fired 4.15 seconds later (Z312) by a pro on the roof of the County Records Building, using a fragmenting, hollow point .257 Roberts bullet in the .30 caliber shell found years later on the roof of the CRB (i.e., a sabot). The lead core of this third shot is what caused Connally’s wrist injury. The fourth shot, which missed completely, was fired by Oswald ¾ of a second later and caused the damage to the curb and Tague’s injury.
In the abstract, something like this seems to me to be by far the most plausible conspiracy theory – i.e., Oswald does pretty much exactly what the LN narrative posits him doing, but a pro firing on roughly the same trajectory with a highly fragmenting bullet makes sure the job gets done. Or perhaps the other gunman wasn't a pro but simply had a better rifle. Perhaps Oswald was a patsy in the sense of thinking he was involved in a pro-Castro plot when it was actually something else, or perhaps it was actually a pro-Castro plot and the other gunman was aligned with Oswald.
Orr’s theory as to how this all worked seems less plausible. The conspirators were unspecified “skilled professionals.” Basically, Oswald had been setting himself up far in advance to take the blame for the JFKA, as well as making sure he was seen in the sixth-floor window. The plan was for him to escape along with the pro and for the JFKA to be blamed on him as the “obvious” assassin – not as a patsy per se, but as the lone gunman when there in fact were two. If Oswald had managed a kill shot, the pro would not have fired at all. When the pro was forced to take the kill shot, Oswald quickly fired the fourth shot to cover the pro’s tracks. Both were under instructions to escape the scene as quickly as possible.
This all sounds fantastically improbable to me. If the Mafia had planned it all and had duped Oswald into thinking the pro were a fellow Castro supporter, which I suppose might be consistent with what Orr is saying, this would be halfway plausible. It still all seems like ad hoc speculation – i.e., Dealey Plaza is what occurred, so we have to fit our conspiracy theory into it. All the risks associated with Oswald in the TSBD, and the complete lack of anything resembling a rational escape plan, seem to me almost impossible to square with “skilled professionals.” I mean, just shoot JFK from the CRB or Dal-Tex building and leave behind some sort of pro-Castro manifesto; much simpler and less risky, no? Why do we need Oswald and all the risks his participation from the TSBD would entail? We need this because it's what happened and thus our after-the-fact ad hoc theory must address it somehow.
Anyway, Orr’s analysis is very interesting. Make of it what you will if you haven’t seen it before.