Destiny Betrayed: (page 294)
Ok, let's go over his evidence. First up is Richard Case Nagell: (page 294)
"For instance, Richard Case Nagell had a grenade thrown at him from a speeding car in New York. Nagell brought the remains of the grenade to Garrison and told him he did not think it was wise for him to testify at Shaw's trial."
DiEugenio's source is page 436 of Dick Russell's book
The Man Who Knew Too Much:
There are several problems with this story. First, Richard Case Nagell had serious credibility issues. Over the years, he repeatedly claimed to have secret evidence regarding the assassination, and nothing ever turned up. Second, there is no corroboration for this grenade story from anywhere - no press stories, no memos, and no one associated with the Garrison investigation talked about this. Third, Jim Garrison himself has a very different story about Nagell and the Shaw trial in his book