AS the world marks the 50th anniversary of JFK's assassination attention has turned to the Co Tyrone man who was driving his car the day he was shot dead.
Over the past five decades William Greer has become the focus of conspiracy theories that he may have played a part in the iconic US president's death.
Originally from Stewartstown, between Cookstown and Coalisland, Greer moved to America with his family in 1929.
After holding down several driving jobs he eventually joined the US Navy before leaving in 1945.
Within weeks he was enlisted to the US secrecy service where he went on to protect some of the most powerful men in America.
As well as working with President Kennedy, he also acted as a bodyguard for presidents Truman and Eisenhower.
But it's Greer's connections with the north that have fuelled some of the more bizarre conspiracies that claim he had a role to play in the popular Irish-American president's assassination.
Greer was brought up a Protestant and is believed by some to have held anti-Catholic views.
It is reported that when asked what his father thought of President Kennedy, in a 1991 interview Greer's son Richard replied: "Well we're Methodists... JFK was Catholic".
Some conspiracy theorists say this could be the motivation for his possible involvement in the shooting of Kennedy as his cavalcade passed through Dallas on November 22 1963.
The most outlandish theories claim that Kennedy's Tyrone-born driver even fired the fatal third head-shot that killed the president.
Whether Greer was involved in the murder of Kennedy will probably never be known.
Regardless, his reactions on the day of the shooting have been questioned in the intervening years.
Former secret service man Clint Hill, who rushed to Kennedy's car after he was shot, later said he had to scream at Greer to accelerate away from the scene of the shooting.
In the years after the assassination others were also critical of his slow reactions.
A special assistant to Kennedy, Kenneth O'Donnell, later wrote: "If the Secret Service men in the front had reacted quicker to the first two shots at the president's car, if the driver had stepped on the gas before instead of after the fatal third shot was fired, would President Kennedy be alive today?"
Former US president Lyndon B Johnson and Jacqueline Kennedy were both later said to have been critical of Greer's reactions.
A recently published book, The Kennedy Detail, written by former secret service man Gerald Blaine, has also focused on Greer's slow reactions.
After leaving the secret service in 1966 due to a stomach ulcer William Greer later moved to North Carolina where he died aged 75 in 1985.
Over the years many theories have emerged as to why Kennedy was shot and who carried the killing out.
The man blamed by US authorities for his murder, Lee Harvey Oswald, was himself gunned down by nightclub owner Jack Ruby while in police custody two days after the president's death.
The Warren commission, set up to investigate Kennedy's assassination, later found that Oswald a former US Marine, acted alone - a conclusion rejected by some.