Josiah Thompson wrote Six Seconds in Dallas in 1967 after three years of intense research and investigation. It is chock full of valuable information.
I don't know if it's available on line, but I'm sure most libraries still have copies of it......
If you've read it there are a couple of points that i'd like to discuss.
‘Six Seconds in Dallas’ may be found on line at:
https://archive.org/details/SixSecondsInDallas/page/n103/mode/2upThere may be some confusion over page numbers. The page numbers shown on the bottom of the screen, to the right go from page 1 through 348. I will refer to these numbers as ‘Computer’. These are different then the page numbers printed in the book, which I refer to as ‘Book’.
Below are the two most useful sections of the book:
Page 105 (Computer) or Page 91 (Book) shows the position of JFK’s head from z301 through 330 with a couple of graphs.
Appendix B and C, which was prepared by Physics graduate student William Hoffman appears on Pages 286-291 (Computer) or Pages 272-277 (Book)
These are the two sections that are the most valuable parts of this book, the sections based on the work by William Hoffman.