Robert F Kennedy Jr is once again making waves after accusing former Lockheed Aircraft employee Thane Eugene Cesar of murdering his father.

'On June 5, 1968, Cesar, an employee in a classified section of Lockheed’s Burbank facility, was moonlighting as a security guard at the Ambassador Hotel. He had landed the job about one week earlier,' wrote RFK Jr in a social media post on Thursday.

'Cesar waited in the pantry as my father spoke in the ballroom, then grabbed my father by the elbow and guided him toward Sirhan.'

He made this accusation just hours after Cesar passed away in the Philippines, and 41 years after the fatal shooting.

RFK Jr also claimed that it was Cesar, unloading his gun from behind as Kennedy fell to the floor after being struck with a bullet from Sirhan's gun, who fired the fatal shot that night.

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Gunman: Robert F Kennedy Jr is accusing Thane Eugene Cesar (above on night of assassination) of murdering his father, claiming he fatally shot the presidential hopeful from behind in 1968

Tragedy: He is also claiming that Cesar fired the fatal bullet that night, saying the security guard shot Kennedy from behind after planning the murder with Sirhan Sirhan (Kennedy above after the shooting with hotel employee Juan Romero by his side and Cesar's clip-on tie near his right)

Conspiracy: There are others who believe there were two gunmen that night, a theory that was bolstered when the coroner determined Kennedy was shot from behind (Cesar and Kennedy in the only known shot of the two together, with the guard circled in red)

RFK Jr is not the first to accuse Cesar of having been involved in the assassination, with some even believing it was his bullet and not Sirhan's which killed the presidential hopeful.

Convicted: Sirhan Sirhan (above in mugshot) is serving a life sentence for the murder

He had been called in to work at the hotel at the last second that night, with the plumber at Lockheed also working security detail part time with a local agency.

Many have pointed out in the past that Thane had extreme right-wing views and held a deep-seeded hatred for the Kennedy clan.

And it is true that he was standing by the then-New York senator's side at the exact moment he was shot by Sirhan.

His gun was drawn as well at the time, and powder burns were found on his face.

And hios clip-on tie was found by Kennedy's side, as if he had ripped it off while being shot

Cesar was married at the time

There has long been support for the theory that there was a second gunman however after the autopsy report found that Kennedy died after being fatally struck from behind.

RFK Jr notes that in his post, which comes just a few months after he made waves with his sudden and staunch stance against mandatory vaccinations.

WAS BOBBY KENNEDY SHOT BY A SECOND GUNMAN? Sirhan Sirhan is the only person who was charged and tried in the wake of of Robert F Kennedy's assassination, but there is some evidence that does support the theory of a second gunman. At the same time, there are also some less certain observations that could back this claim from those in attendance that fateful night. -ENTRY POINTS : Kennedy was shot three times according to the autopsy report. One bullet entered through his armpit, one entered through his back and one through the back of his head behind his right ear. Sirhan Sirhan was stood in front of Kennedy at the time of the shooting. -FATAL BULLET: The bullet which had entered through Kennedy's head and was determined to have caused his death one day after the shooting was fired at point black range. -SHOTS FIRED: In video of the incident, there are what sounds like 11 shots being fired in total, but Sirhan would have been able to fire no more than eight. -SIRHAN'S CAPTOR: The individual who tackled Sirhan to the ground first and multiple eyewitnesses have said that the convicted murderer only got off two shoots before he was tackled to the ground. That is when he fired the shots that injured members of the crowd. Three bullets struck Kennedy, and a fourth went through his jacket. -BLANKS: One eyewitness said that paper could be seen in the air after Sirhan fired his bullets, suggesting he was using blanks. The Palestinian-born stable boy has said he does not even remember the shooting, leading some to believe he may have been hypnotized by the CIA. -CIA: There are some who believe that the assassination was the work of Robert A. Maheu, a former FBI agent who would complete assignments for the CIA. he was also the boss of Thane Eugene Cesar the LAPD learned after the shooting. Advertisement

'Sirhan fired two shots toward my father before he was tackled. From under the dog pile, Sirhan emptied his 8 chamber revolver firing 6 more shots in the opposite direction 5 of them striking bystander and one going wild,' wrote RFK Jr.

'By his own account, Cesar was directly behind my dad holding his right elbow with his own gun drawn when my dad fell backwards on top of him. Cesar repeatedly changed his story about exactly when he drew his weapon.'

He then added: 'According to the Coroner, Dr. Thomas Noguchi, all 4 shots that struck my father were “contact” shots fired from behind my dad with the barrel touching or nearly touching his body.'

RFK Jr then gets into what Cesar did with the murder weapon and his motive for the murder.

'Cesar sold his .22 to a co-worker weeks after the assassination warning him that it had been used in a crime. Cesar lied to police claiming that he'd disposed of the gun months before the assassination,' claimed RFK Jr.

'Cesar was a bigot who hated the Kennedys for their advocacy of Civil Rights for blacks.'

He then revealed that he had even planned to meet Cesar last June in the Philippines, but said that the planned sit-down was cancelled at the last second.

RFK Jr said that it was Cesar's agent, Dan Moldea, who cancelled the meeting.

That is the same man who first gave weight to the theory that Cesar might have played a role in the shooting back in 1995, when he published The Killing of Robert F. Kennedy: An Investigation of Motive, Means, and Opportunity.

The investigative journalist and author laid out all the evidence in support of the second gunman theory, but then declared Cesar was not guilty of any crime in the book's final pages.

Moldea also eulogized Cesar on Thursday, but in a far different tone than RFK Jr.

'Thane Eugene Cesar, 77, the security guard falsely accused of killing RFK in June 1968, has just died,' wrote Moldea.

'Attached is an excerpt of my 12th interview with him. BTW: I am the only person in the world who has interviewed both Cesar and Sirhan Sirhan, who did it and did it alone.'

Wife: Ethel Kennedy (above in the foreground attending to her husband) was with the sentaor when he was shot

Timing: RFK Jr (left in December, right at his father's funeral) made this accusation just hours after Cesar passed away in the Philippines, and 41 years after the fatal shooting.

This is not the first time RFK Jr has flouted this theory, and he is not the only member of his family who believes Cesar is responsible for his father's death.

His sister Kathleen Kennedy Townsend, who served as lieutenant governor of Maryland from 1995 to 2003, has also said in the past that police should reopen the investigation into her father's murder.

THANE EUGENE CESAR KILLED ROBERT KENNEDY SAYS RFK JR VERSION OF EVENTS 'Thane Eugene Cesar died today in the Philippines. Compelling evidence suggests that Cesar murdered my father. On June 5, 1968, Cesar, an employee in a classified section of Lockheed’s Burbank facility, was moonlighting as a security guard at the Ambassador Hotel. 'He had landed the job about one week earlier. Cesar waited in the pantry as my father spoke in the ballroom, then grabbed my father by the elbow and guided him toward Sirhan. With 77 people in the pantry, every eyewitness said Sirhan was always in front on my father at a 3-6 feet distance. 'Sirhan fired two shots toward my father before he was tackled. From under the dog pile, Sirhan emptied his 8 chamber revolver firing 6 more shots in the opposite direction 5 of them striking bystander and one going wild . By his own account, Cesar was directly behind my dad holding his right elbow with his own gun drawn when my dad fell backwards on top of him. Cesar repeatedly changed his story about exactly when he drew his weapon. 'According to the Coroner, Dr. Thomas Noguchi, all 4 shots that struck my father were “contact” shots fired from behind my dad with the barrel touching or nearly touching his body. Cesar sold his .22 to a co-worker weeks after the assassination warning him that it had been used in a crime. 'Cesar lied to police claiming that he'd disposed of the gun months before the assassination. Cesar was a bigot who hated the Kennedys for their advocacy of Civil Rights for blacks. 'I had plans to meet Thane Eugene Cesar in the Philippines last June until he demanded a payment of $25,000 through his agent Dan Moldea. Ironically, Moldea penned a meticulous and compelling indictment of Cesar in a 1995 book and then suddenly exculpated him by fiat in a bizarre and nonsensical final chapter. 'Police have never seriously investigated Cesar's role in my father’s killing.' INVESTIGATION 'The LAPD unit (SUS) that investigated my dad’s assassination was run by active CIA operatives. They destroyed thousands of pieces of evidence. Sirhans appointed lawyer was Johnny Rosselli’s personal lawyer,Grant Cooper. Roselli was the mobster who ran the assassination program for the CIA against Castro. Cooper pressured Sirhan to plead guilty so that there was no trial. Sirhan, to this day, has no memory of the assassination.' Advertisement

'The LAPD unit (SUS) that investigated my dad’s assassination was run by active CIA operatives. They destroyed thousands of pieces of evidence,' RFK Jr later noted.

'Sirhan's appointed lawyer was Johnny Rosselli’s personal lawyer, Grant Cooper. Roselli was the mobster who ran the assassination program for the CIA against Castro. Cooper pressured Sirhan to plead guilty so that there was no trial.'

Then, in what may be his most bombastic claim of all, RFK Jr stated: 'Sirhan, to this day, has no memory of the assassination.'

Sirhan has claimed this as well multiple times in the past, despite his conviction by a jury one year after the shooting.

No other gunman was ever apprehended or charged with playing a role in the assassination.

The investigation was ultimately closed out one year after the shooting in 1969, when Sirhan was convicted of he crime.

He was first sentenced to death, but that was commuted to a life sentence just a few years later in 1972.

He is now 75 and incarcerated at the Richard J. Donovan Correctional Facility in San Diego.

Sirhan has lost all of his legal appeals and repeated bids for parole.

Prosecutors were able to present evidence suggesting Sirhan was seen at the hotel two nights before the attack.

He was also holding the same gun from which the bullets that killed Kennedy came from, and had eight additional bullets in his hand.

On the opposite side of the debate are RFK Jr's siblings Joseph and Kerry, the latter of whom recently took her brother to task earlier this year following some of his comments about vaccinations.

This is not because the two do not believe the theory, but rather how they want their father to be remembered by the public.

Kerry previously stated: 'The reason that people are interested in the circumstances of my father’s death is because of what he did with his life. And I think we should focus on his life and not so much on his death — his moral imagination, his capacity for empathy, his quest to heal divisions, and his belief that one person can make a difference.'

Joseph, who is named after the family patriarch and his uncle who died in World War II, echoed this sentiment, and in a statement last year wrote: 'As we approach the 50th anniversary of my father’s passing, I think what is most important is that our country and my family reflect on what my father stood for and fought for — a legacy promoting global peace, social justice, and civil rights.'

Kennedy had just won the California primary and his pregnant wife Ethel was by his side when he was shot.

He died one day later.

Kennedy was hit with three bullets - one in the head and two in the back - while fourth passed through his jacket.

Five others were shot but recovered from those injuries.