LOS ANGELES, United States (AFP) — The man convicted of shooting dead Robert Kennedy in 1968 will not be released from prison, after California Governor Gavin Newsom on Thursday denied his request for parole.

Sirhan Sirhan, now 77, has been behind bars for five decades — despite doubts that he fired the shots that likely changed the course of US politics.

Kennedy, the younger brother of slain president John F. Kennedy, was campaigning for the Democratic nomination himself when he was gunned down in a Los Angeles hotel.

A California parole board greenlit Sirhan’s request in August 2021 — after 15 previous denials — but the final decision rested with the governor, who ultimately said that Sirhan “poses an unreasonable threat to public safety.”

According to a statement released by the governor’s office, Newsom based his decision on several factors, “including Mr. Sirhan’s refusal to accept responsibility for his crime.”

Sirhan was convicted and sentenced to death in 1969 after pleading guilty, but his sentence was commuted to life imprisonment several years later.

Doubts around Sirhan’s culpability have swirled since his trial, when it was revealed that Kennedy was shot at point-blank range from behind, but witnesses said Sirhan was standing in front of him.

Later, evidence emerged that as many as 13 shots were fired, yet Sirhan’s gun could only hold eight bullets.

Suspicion over the verdict led Kennedy’s son, Robert F. Kennedy Jr, to visit Sirhan in prison.

“I went there because I was curious and disturbed by what I had seen in the evidence,” he told the Washington Post in 2018.

“I was disturbed that the wrong person might have been convicted of killing my father.”

He and his youngest brother, Douglas, supported Sirhan’s most recent attempt at release.

Kennedy’s widow, the 93-year-old Ethel Kennedy, disagreed, and called on the governor to keep Sirhan imprisoned, saying in a Twitter statement that “he should not have the opportunity to terrorize again.”

Newsom said in a statement that Kennedy’s assassination “is among the most notorious crimes in American history.”

“After decades in prison,” Newsom added, Sirhan “has failed to address the deficiencies that led him to assassinate Senator Kennedy.”

A Palestinian immigrant, Sirhan said at the time of the assassination that his actions were motivated by Kennedy’s support for military sales to Israel.

During his last parole hearing, in 2016, he stated that he had drunk too much the night of the shooting, and that his prior confession was the result of bad legal advice from his lawyer.

© Agence France-Presse