Following the 1963 assassination of President Kennedy, the Warren Commission established that one of the three shots fired in Dealey Plaza missed. By 1979, subsequent investigations determined that the first shot fired was the one that missed. Left unanswered was why the first shot missed and how to explain phenomena associated exclusively with the first shot.

A traffic signal assembly, under which the presidential vehicle traveled, could have obstructed the first shot but was never technically examined. Beginning in 2010, this assembly was subjected to a number of forensic examinations, including rifle test firings on exemplars. From these findings, it is concluded that the most reasonable explanation for why Lee Harvey Oswald’s first shot missed is that the bullet struck the mast arm of the signal light and was redirected on its flight path, eventually to a concrete curb where the FBI found evidence of a bullet impact.