A former mob hitman is coming forward once again to say that he is the man who killed President John F. Kennedy.

James Files says that he was the man on the grassy knoll back on November 22, 1963, and that he fired the bullet into Pres. Kennedy's head that ultimately killed him.

He says the other shot that hit Pres. Kennedy came from his boss, Charles 'Chuckie' Nicoletti, who was hiding out in the book depository, the same place Lee Harvey Oswald is believed to have been at the time of the shooting.

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Confession: James Files (above) says he is the man who assassinated Pres. John F. Kennedy

New claim, again: Files has claimed before that he was in Dallas, Texas on November 22, 1963, firing the shot that ended the life of Pres. Kennedy as he drove through on his motorcade (above)

Location: Files says he took his shot from the infamous grassy knoll (seen in the background above)

Files also says that Oswald, who was charged, but then shot dead before he could be tried or convicted in the killing, never filed a single shot.

He described what happened in a new documentary that aired on Newsmax TV, I Killed JFK.

He says he chose the grassy knoll so he could pretend to be a worker at a nearby rail yard, and come and go without being noticed.

Then, as Pres. Kennedy's motorcade approached, he sprung into action.

'I was aiming at his right eye. When I pulled the trigger it was almost like looking from six feet away through the scope,' he explains.

'As I squeezed his head moved forward. I missed and got it right along the temple, right behind the eye. I squeezed off my round. I hit him and blew his head backward. I fired one shot and one shot only.'

He then walked off with no one noticing, not even the two police officers he claims were standing 25 feet away.

Hideout: Files also claims his boss, Charles “Chuckie” Nicoletti, was in the nearby book depository (above), and not Lee Harvey Oswald

Convicted: In the end, Oswald (above) was charged with the murder

He did however leave a trinket, biting down on the shell casing that came from his gun.

The documentary claims that casing matches one a young boy and his father found buried in the knoll over 20 years later.

At least one former FBI agent, Zack Shelton, believes Files story, including the location from which he shot Pres. Kennedy.

'I have tried to verify Files' story. A lot of that story I have been able to verify,' says Shleton.

Five government investigations since the assassination have determined it was Oswald who shot Pres. Kennedy.

Files, who has told this story many times before, including in a 2010 interview with Playboy, is currently serving a 50 years sentence following a 1991 conviction for the attempted murder of two police officers during a roadside shootout.