There is a great documentary on Netflix called "The Men Who Killed Kennedy". 4 part series that covers a ton of info on this. If you have a Netflix account you can stream it from their site. (Buy it here http://tinyurl.com/2bwk3pv it's worth it.)
The documentary was made in the 90's and some of the info may have been challenged, but it is a great show to watch. I'd say 90% of it is accurate.
This is a fascinating subject with plenty of unusual turns. It is highly unlikely Lee killed Kennedy.
All of the doctors said the back of his head was blown off yet the Warren commission photo shows only one small entry wound on the back of the head. Inconsistent with the reports.
If you get a chance either rent or buy this doco, it's well worth watching.