A man is shot. A man dies.

Everyday stuff, unfortunately. Most of the victims merit a story in the local newspaper and are quickly forgotten.

The shooting of John F. Kennedy, in contrast, continues to resonate 40 years after the fact. Part of the reason is the obvious — the man was president of the United States, the most powerful political figure in the world. That alone upgrades the incident's description from "murder" to "assassination."

But that's only part of it. There have been many assassinated world leaders, the vast majority of them failing to elicit as much fascination and curiosity (morbid and otherwise) as Kennedy. And there are good reasons.

For one, JFK's death was, if there is such a thing, the perfect tragedy. Images of a beautiful, grieving widow, a 3-year-old boy saluting his father's casket, a leader struck down in the prime of his life — Kennedy's life and, especially, death were Shakespearean in scope.

"It sticks with us because it has all the elements of tragedy and martyrdom," Utah State University President Kermit Hall, a historian, said. "Here's a person who's young, ambitious, articulate, a war hero, two young children, a strong presence. All of that contributes to it."

There's more to it, though. The Warren Commission, which concluded one year after the 1963 shooting that Lee Harvey Oswald acted alone, was unable to bolster its conclusions with facts because the documents it relied on were largely classified. Hall himself helped declassify 99.8 percent of those documents during the 1990s as a member of the John F. Kennedy Assassination Records Review Board, but the damage had already been done.

With 1960s officialdom unwilling or unable to explain itself, theories involving, among much else, Cuba, the USSR, Jack Ruby, Mexico, the mob and the CIA filled in the gaps. Those theories have thrived over the years, resulting in a literal Kennedy assassination market economy: countless books, a hugely influential movie (Oliver Stone's 1991 "JFK," which spurred the creation of the review board), the only assassination museum in the United States (in Dallas), magazine articles and discussion groups.

"Americans have long had a penchant for believing in conspiracy," Hall said. "The uncertainty surrounding the assassination influenced how we explained it."