The agent was actually Mrs Kennedy's personal bodyguard. She knew him well and he was highly trusted. I can not remember his name but he is still alive. Now you watch the Zapruder film, Kennedy was shot twice. Which is confirmed. The first time he starts to sort of kneel down. This is when Jackie's body guard started for the car who was on the car behind them from Kennedy's orders. So that is the agent part of it. Now Kennedy was shot from the behind of the head but then again you should see something. Brain parts, blood, etc something that shows injury but your right it does not. Same with Mrs Kennedy. I agree it is a interesting photo.