Both of these books are probably the two leading books dismantling the case that Jim Garrison made against Clay Shaw. The question is - what is the difference between these two books and which one is better? Or perhaps there is a third option and both books should be read (if they both offer something unique). But I would prefer to read only one book on this topic as Jim Garrison seems to be a fraud so I don't want him taking up too much of my time.
Here is a video promo for "On The Trail of Delusion":
And here is the documentary that was made based on Patricia Lamberts book "False Witness":
As Fred Litwin pointed out above, the Lambert book focuses almost exclusively on the Clay Shaw trial and investigation by Garrison and little else. If you want to read about Garrison's other outrageous and corrupt behavior during the matter - his other claims about the CIA and a long list of people he smeared and defamed - then it's probably better to read Mr. Litwin's book. Lambert, who died I believe
just 3-4 years a few years ago (and didn't release, as far as I know, any updated version), believed that there was a conspiracy in the assassination and that it involved elements of the Mob, e.g., Marcello et al. Mr. Litwin doesn't believe there is evidence showing a conspiracy.
Here's a good overview of the Lambert book written by the first reporter to break the story that Garrison was investigating the assassination, Rosemary James. Link:
https://mcadams.posc.mu.edu/james_on_lambert.htmJames covered the whole farce from beginning to end. She first broke the story and then was stunned that the next day or two dozens of reporters from around the world showed up in New Orleans looking into the matter. Surprisingly she says that every time someone suggested a possible role by the Mob into the assassination that Garrison vehemently shut the issue down. You could suggest Martian leprechauns were involved and that was acceptable; but if you broached the possibility of any Mob role - however small - Garrison would stop the discussion immediately. Very odd.
If you really want to get into the tall grass about Shaw, you can read Donald Carpenter's incredibly detailed book on him called "A Man of a Million Fragments." That gives almost a weekly if not daily account of Shaw's life. Shaw was a fascinating man; very intelligent and extremely hard working. He was drafted into the Army in 1942 and left it in 1946 as a Major. Yes, he went from a private to a Major - and was highly decorated (Bronze Star, Legion of Merit, et cetera) despite seeing no combat - in four short years. Although calling a year in a war a "short year" is probably wrong. And when he came back he single-handedly put together the Trade Mart, working on its design and seeing through its completion and then spending years promoting it around the world.
BTW, I deleted the videos to save space/bandwidth.