This book, The Man Who Knew Too Much: Hired to Kill Oswald and Prevent the Assassination of JFK, was a very fascinating book when I read it back in the 1993 or so when it first came out. There is apparently an updated version now.
I came across this synopsis of it today and it jogged my memory about Richard Case Nagell who, in September of 63, went into a federal bank and fired two shots into the ceiling in order to get arrested because he wanted to be in jail when Kennedy was shot so that no one could blame him for it. The rest you will have to read for yourself.
I tend to be a skeptical person, though I prefer that you call me discerning (or wise wouldn’t be a bad option either).
But no matter what you call me, if you have any interest in the Kennedy assassination, this book will be interesting to you.