A worker preparing for the 50th anniversary commemoration of the assassination of President John F. Kennedy pauses to look out over the infamous wooden picket fence at the top of the "Grassy Knoll" in... more 
A worker preparing for the 50th anniversary commemoration of the assassination of President John F. Kennedy pauses to look out over the infamous wooden picket fence at the top of the "Grassy Knoll" in Dealey Plaza down towards a crowd of conspiracy theorists chanting and protesting on the spot where the president was shot as people gather at the site in Dallas, November 21, 2013. The "Grassy Knoll" and the wooden picket fence behind it play a major role in most conspiracy theories about the assassination, with supporters of the theories believing that one or more gunmen fired on the president from the top of the knoll behind the fence in addition to Lee Harvey Oswald, who was behind the president on the sixth floor of the Dallas School Book Depository. Commemorations of the 50th anniversary of the assassination will be held Friday in Dallas, Washington and Boston. REUTERS/Jim Bourg (UNITED STATES - Tags: POLITICS ANNIVERSARY) less 
1 / 24
Reuters | Photo By JIM BOURG / REUTERS
Thu, Nov 21, 2013 7:22 PM EST