David Lifton's 'Best Evidence:' Who done it?

I remember leafing thru this book when it first came out, but I didn’t buy or read it. As I recall, Lifton’s premise is that JFK’s body was altered and there were some switcheroos, etc.
From interviews I seem to recall that Lifton didn’t support the “long gunman” idea, but did he offer in his book which party(ies) he thought were in on the deed?
(And, please note, this is Café Society, not GQ.)

Is a “long gunman” a tall one, like Marshall Dillon?

I read Lifton’s book several years ago, and I don’t recall him accusing any particular party – I think he was just claiming that there was more to the story of what happened to the body and how it was treated after death (which people involved have since denied, I point out). He clearly implies a conspiracy in the handling of the body and keeping quiet about itr, but I don’t recall him fingering who pulled the trigger(s) in the first place. But I may be misremembering.

No. His thesis was that the alteration of the body made it impossible to determine the sponsor of the nefarious deed.

Cool. Thanks.