Why Oswald didn’t do it- in a nutshell

Beyond speculation, is there definite, indisputable proof that Lee Harvey Oswald did not, and could not have fired the fatal head shot that killed JFK?  Researcher and author Dave O’Brien says there is, and he sums up the reasons why in this video.  This is our update to the recent interviews we did with Dave in On-Target with Larry Sparano.  Here it is –in a nutshell: