I sat in the bushes watching the parade go on in front of me. I looked at the crowds and took in so much of the atmosphere that I barely noticed that right on time the motorcade came around the corner. In it the man of the hour waved to the people, smiling, optimistic.
With three seconds left my eye began to look up into the depository as the flash went off. The well known panic filled the streets, the president had been shot.
I guess Oswald did do it; I owed someone at the time travel agency five bucks.