The documents filed this week in federal court and obtained by The Associated Press detail extensive interviews with Sirhan during the past three years, some done while he was under hypnosis.
The papers point to a mysterious girl in a polka-dot dress as the controller who led Sirhan to fire a gun in the pantry of the Ambassador Hotel. But the documents suggest a second person shot and killed Kennedy while using Sirhan as a diversion.
For the first time, Sirhan said under hypnosis that on a cue from the girl he went into "range mode" believing he was at a firing range and seeing circles with targets in front of his eyes.
"I thought that I was at the range more than I was actually shooting at any person, let alone Bobby Kennedy," Sirhan was quoted as saying during interviews with Daniel Brown, a Harvard University professor and expert in trauma memory and hypnosis. He interviewed Sirhan for 60 hours with and without hypnosis, according to the legal brief.
Sandi Gibbons, a spokeswoman for the Los Angeles County district attorney, said prosecutors were unaware of the legal filing and could not comment.
The story of the girl has been a lingering theme in accounts of the events just after midnight on June 5, 1968, when Kennedy was gunned down in the hotel pantry after claiming victory in the California Democratic presidential primary.
Witnesses talked of seeing such a female running from the hotel shouting, "We shot Kennedy." But she was never identified, and amid the chaos of the scene, descriptions were conflicting.
Through the years, Sirhan has claimed no memory of shooting Kennedy and said in the recent interviews that his presence at the hotel was an accident, not a planned destination.
Under hypnosis, he remembered meeting the girl that night and becoming smitten with her. He said she led him to the pantry.
"I am trying to figure out how to hit on her.... That's all that I can think about," he says in one interview cited in the documents. "I was fascinated with her looks .... She never said much. It was very erotic. I was consumed by her. She was a seductress with an unspoken unavailability."
Brown was hired by Sirhan's lawyer William F. Pepper.
Pepper's associate, attorney Laurie Dusek, attended the interviews. and Brown said in the documents they both took verbatim notes because prison officials would not let them tape record nearly all the sessions.
Sirhan maintained in the hypnotic interviews that the mystery girl touched him or "pinched" him on the shoulder just before he fired then spun him around to see people coming through the pantry door.
"Then I was on the target range ... a flashback to the shooting range ... I didn't know that I had a gun," Sirhan said.
Under what Brown called the condition of hypnotic free recall, he said Sirhan remembered seeing the flash of a second gun at the time of the assassination. Without hypnosis, he said, Sirhan could not remember that shot.
Pepper, a New York lawyer with an international practice, previously tried to prove that James Earl Ray was not the assassin of Martin Luther King Jr.
The lawyer said he is convinced that Sirhan was a victim of a mind control project such as those used by the CIA in the 1960s. He is seeking an evidentiary hearing to exonerate Sirhan in Kennedy's killing.
Dusek said in an interview that Sirhan was hypnotized for perhaps 30 percent of the interviews, most of which had to be done through a glass partition with Brown talking to him on a phone.
Only when Sirhan was moved from the state prison at Corcoran to his current location at Pleasant Valley State Prison in Coalinga were they allowed face-to-face visits, she said, and a few of those were recorded.
Other portions of the motion allege suppression of ballistics evidence and the autopsy report, and claim ineffective assistance of counsel. It contends previous lawyers for Sirhan accepted from the start that he was the lone shooter, settled on a defense of diminished capacity and did not seek other avenues of defense.
During the trial, Sirhan tried to confess to killing Kennedy "with 20 years of malice aforethought," but the judge rejected the blurted statement.
A large portion of the new documents seek to prove the bullets that hit Kennedy came from a different direction than the spot where Sirhan was standing. The papers do not name any other possible shooter.
Sirhan was denied parole in March by a panel that said he had not shown sufficient remorse for the killing.