Robert Kennedy and Sirhan Sirhan

One of San Diego's most notorious inmates will remain behind the walls of the state's Donovan Correctional Facility here following a federal judge's ruling that evidence of a possible conspiracy does not absolve Sirhan Bishara Sirhan of guilt in the June 1968 slaying of Robert F. Kennedy.

The convicted assassin "has failed to meet his burden of establishing actual innocence," wrote judge Beverly Reid O'Connell in her January 5 order denying a bid by Sirhan for a writ of habeas corpus.

“Likewise, Petitioner has failed to demonstrate that he falls within the narrow exception warranting an evidentiary hearing at this stage."

The latest in a long string of legal efforts by Sirhan, now 70, was filed in May 2000. Despite multiple rejections by federal courts, his attorneys have continued to appeal the case, asserting in part that others were behind the killing of the Democratic presidential candidate.

"Though Petitioner advances a number of theories regarding the events of June 5, 1968," O'Connell's ruling says, "Petitioner does not dispute that he fired eight rounds of gunfire in the kitchen pantry of the Ambassador Hotel.

"After reviewing the evidence, the Court agrees with the findings of Magistrate Judge Wistrich. Petitioner does not show that it is more likely than not that no juror, acting reasonably, would have found him guilty beyond a reasonable doubt."

Much of Sirhan's latest bid for freedom has been based on testimony of eyewitness Nina Rhodes-Hughes, which was not presented at Sirhan's 1969 trial.

"What has to come out is that there was another shooter to my right," Rhodes-Hughes, a television actress, told CNN in April 2012. "The truth has got to be told. No more cover-ups."

O'Connell's ruling dismisses that argument. "Ms. Rhodes-Hughes disputes the location and number of gunfire shots; yet, importantly, she does not assert that Petitioner is innocent.

"First, Ms. Rhodes-Hughes’s recollection was recorded decades after the events took place, which calls into question its reliability. Second, her declaration confirms that Petitioner was a shooter that evening," the judge wrote.

"Ms. Rhodes-Hughes states that she was in the kitchen, she saw Petitioner fire his gun, and she witnessed men attempt to subdue him. Ms. Rhodes-Hughes does not state that she saw a second shooter.

“She suggests that there was more than one shooter because she counted twelve to fourteen shots rather than eight, and she testifies that gunfire originated in both the left and right sides of the room….

"Ms. Rhodes-Hughes describes how she fainted, was trampled by individuals in the kitchen, awoke with a wet dress, and had one shoe knocked off her foot.

“A jury reasonably may have concluded that witnesses could not be expected to pinpoint the exact location of those two parties in the midst of such chaos."

Questions regarding a second shooter and how many shots were fired have long dogged the case, but O'Connell's ruling rejected evidence presented by skeptics, including an audio tape of the assassination that one expert witness has maintained proves there were two shooters.

"At most, Petitioner creates a sense of doubt about the number of gunshots fired in the kitchen on June 5, 1968," said the judge, "but contemporaneous eyewitness statements do not support a second shooter theory."

Arguments that Sirhan was hypnotically programmed, perhaps by the Central Intelligence Agency or other anti-Kennedy government or mob actors, were also rejected.

Sirhan’s next legal steps have not been announced, but the latest ruling is unlikely to silence skeptics, who have included one-time San Diego Tribune reporter Robert Blair Kaiser and author of the book R.F.K. Must Die.

"I am more convinced than ever that Sirhan Sirhan didn’t think this up all by himself, and that he killed Kennedy in a trance," writes Kaiser in the epilogue to the 2008 edition of the book.

"Yes, that he was programmed to kill Senator Kennedy and programmed to forget he was programmed. Of course Sirhan was lying much of the time. He was programmed to lie. That was part of the cover-up.

"Of course, he was a psychotic when he killed Kennedy. His programmers induced the psychosis. But it only lasted for a time. Sirhan worked through that sickness (if you need to call it that) as he gradually came to see himself as an Arab hero, giving himself a sense of importance that he had never felt before."