DALLAS - About 300 people, including history buffs, conspiracy theorists and even two Elvis impersonators, gathered in Dealey Plaza on Wednesday to mark the 43rd anniversary of President Kennedy's assassination in a loosely organized ceremony that was part memorial and part circus.

Mickey Castro takes a picture in Dealey Plaza in Dallas, Wednesday, Nov. 22, 2006. About 300 people, including Elvis impersonators and artists working on a peace exhibit, gathered on the 43rd anniversary of President Kennedy's assassination. [AP]

Beverly Oliver, who witnessed the Nov. 22, 1963 shooting, began the event by singing the national anthem, after which the crowd observed a moment of silence at about 12:30 p.m., the time of day Lee Harvey Oswald is believed to have fired the fatal shots.

Many on hand, however, said they didn't think Oswald acted alone in Kennedy's assassination and some thought he was set up.

"You'll get 100 different theories from 100 different people," said Jim Crump, a 44-year-old stagehand from Orlando who said he was working on an "in-depth study" of the assassination. "It's like Pandora's Box, where more and more stuff comes out until you just can't get it to close and go away."

Author Robert Groden, a Dealey Plaza regular for the past 12 years, hawked his 11 books and glossy magazines about the assassination from a table set up between the grassy knoll and Elm Street, where Kennedy and Gov. John Connally were shot.

He believes the shooting was the result of an "unholy alliance" between the CIA and organized crime and that eight to 13 shots were fired that day, with several coming from the grassy knoll and the parking lot behind it.

A group billing itself as the Coalition on Political Assassinations held aloft a banner bearing the name of its organization. Men milled around wearing T-shirts that said "Who shot JFK?" on the front and "Not LHO" on the back.

Dennis and Debra Walker of Chicago were in town to visit their daughter for Thanksgiving. Dennis, a 54-year-old history teacher, said they came to Dealey Plaza because "this morning it dawned on us that it was the anniversary."

"JFK always had this mystique," said Debra Walker, 50. "It became a part of your life. It became more personal. I remember my parents, who were staunch Republicans, were so devastated and couldn't believe anyone would do this."