Dealy plaza

We toured a part of history, Dealy Plaza where JFK was shot. The book depository now has a museum on the sixth floor, the floor where Oswald allegedly shot the president. An audio tape of the museum is included in the admission. No photographs allowed in the museum. After we toured the museum, we went down to the grassy knoll. There was a gentleman there who says he was there the day Kennedy was shot. He says he saw the smoke from the shots fired from the grassy knoll. Was there a conspiracy or was Oswald the lone shooter? If the head shot came from the front, then was that part of JFK's skull that was recovered by the lamp post? Did someone fire at the president behind the picket fence?