According to Dr. McClellan’s handwritten statement, the bullet entered the left front at the hairline and exited the right rear.Italics are mine.
McClelland:
“This is why it would be difficult to say with certainty as has been implied in some newspaper articles that quoted me, that you could tell for sure that this was
an entrance or an esit wound.”
https://www.history-matters.com/archive/jfk/wc/wcvols/wh6/pdf/WH6_McClelland.pdf