Los Angeles (CNN) -- Sirhan Sirhan, convicted of the 1968 assassination of presidential candidate Sen. Robert F. Kennedy, should be freed from prison or granted a new trial based on "formidable evidence" asserting his innocence and "horrendous violations" of his rights, defense attorneys said in federal court papers filed this week.
In a U.S. District Court brief, Sirhan's lawyers also say that an expert analysis of recently uncovered evidence shows two guns were fired in the assassination and that Sirhan's revolver was not the gun that shot Kennedy.
Attorneys William F. Pepper and Laurie D. Dusek also allege that fraud was committed in Sirhan's 1969 trial when the court allowed a substitute bullet to be admitted as evidence for a real bullet removed from Kennedy's neck.
The attorneys further assert that Sirhan was hypno-programmed to be a diversion for the real assassin and allege that Sirhan would be easily blamed for the assassination because he is an Arab. Sirhan, 67, is a Christian Palestinian born in Jerusalem whose parents brought him and his siblings to America in the 1950s.
Sirhan "was an involuntary participant in the crimes being committed because he was subjected to sophisticated hypno programming and memory implantation techniques which rendered him unable to consciously control his thoughts and actions at the time the crimes were being committed," court papers said.
The California Attorney General's office declined to comment Saturday on Sirhan's court filings, said spokeswoman Lynda Gledhill.
Court papers filed by Sirhan's attorneys say the state "refuses to acknowledge that hypno programming/mind control is not fiction but reality and has been used for years by the U.S. military, Central Intelligence Agency and other covert organizations.
"Though the practices of hypno programming/mind control is hardly new, the public has been shielded from the darker side of the practice. The average person is unaware that hypnosis can and is used to induct antisocial conduct in humans," Sirhan's court filings say.
Pepper and Dusek represented Sirhan earlier this year in his unsuccessful request for parole from Pleasant Valley State Prison in Coalinga, California, 200 miles northwest of downtown Los Angeles. He is serving a life sentence.
Sirhan was convicted of killing Kennedy and wounding five other people during the June 5, 1968, shooting inside the kitchen service pantry of the former Ambassador Hotel in Los Angeles.
Three bullets struck Kennedy's body while a fourth bullet passed harmlessly through the shoulder of his suit coat. Kennedy, the most seriously wounded of the six victims, died the next day. The other five people survived their wounds.
The substitute bullet presented at trial was portrayed as like one removed from Kennedy's neck and matching Sirhan's gun, his attorney said.
Pepper and Dusek are requesting a hearing to present dramatic new findings that they say show a kitchen crossfire in the hotel.
An analysis of a recently uncovered audiotape of the assassination shows that in addition to the eight gunshots fired by Sirhan's Iver-Johnson handgun, five other shots were fired by a second gun from the opposite direction, Sirhan's attorneys said.
The sound recording "clearly showed that 13 shots were fired in the pantry, and Sirhan's gun had only eight shots, so it definitely means there was a second shooter," Pepper told CNN.
The tape was made 40 feet away from the crime scene by freelance newspaper reporter Stanislaw Pruszynski and is the only known recording of the gunshots fired in Robert Kennedy's assassination. The recording was uncovered in 2004 by CNN's Brad Johnson, who had it independently examined by two experts, Spence Whitehead and Philip Van Praag. They concluded, individually, that more than eight shots were captured in the tape. Johnson reported on their separate findings for CNN's "Backstory" in June 2009.
In their court filings, Pepper and Dusek are focusing on Van Praag's analysis. Van Praag concludes that the Pruszynski recording is authentic and reveals that, over a five-second period in the pantry, two guns fired 13 shots, exceeding the capacity of the eight-shot Iver-Johnson Cadet -- the only gun that Sirhan possessed and had no opportunity to reload.
Van Praag rules out the possibility that any of the 13 shots were echoes, ricochets or non-gunshot sounds. He also finds that some of the shots were fired too rapidly, at intervals too close together for all the shots to have come from Sirhan's inexpensive handgun. Van Praag further concludes that the five shots fired opposite the direction of Sirhan's eight shots displayed a "frequency anomaly" indicating the second gun's make and model were different from Sirhan's weapon.
Pepper said that witnesses reported Sirhan was standing several feet in front of Kennedy and firing nearly horizontally while the medical evidence showed Kennedy's body and clothing were struck by four bullets fired point-blank from behind the Senator at steep upward angles.
Pepper said witnesses reported that bystanders grabbed Sirhan immediately after he fired his first two shots and that they had his firing arm pinned against a steam table, forcing Sirhan to fire his gun's remaining six bullets away from Kennedy, thus striking other people instead.
For decades following the 1968 assassination, Sirhan had claimed he could not remember the Kennedy shooting. Pepper and Dusek argue this is because he was "hypno-programmed" to fire his gun in the pantry and to then forget the shooting, his programming and those who had programmed him.
In 2008, Pepper hired a Harvard University memory expert who says he got the imprisoned Sirhan to recall the Kennedy shooting for the first time.
That expert is Daniel Brown, an associate clinical professor in psychology at Harvard Medical School who submitted a statement to the parole board after interviewing Sirhan for 60 hours over a three-year period. Brown says Sirhan now remembers that when he fired his shots in the pantry he believed he was at a gun range and shooting at circular targets, according to Pepper.
Brown believes Sirhan was programmed to do this so as to cause a distraction in the pantry, allowing a second gunman to secretly shoot Kennedy from behind, according to Sirhan's attorneys. Brown is described in Sirhan's court papers as "one of the world's foremost experts in hypno programming."
Brown says Sirhan now remembers hearing loud sounds he describes as "the thunderclap of other bullets" being fired by another gun in the pantry, the defense attorneys said. Brown says Sirhan also recalls seeing flashes in front of him that he associates with gunfire inside the pantry but not coming from his own weapon, according to Pepper.
Pepper accused both prosecutors and Sirhan's lead attorney, Grant Cooper, who has since died, of misconduct in the 1969 trial. At that time, Cooper was under federal indictment for illegally possessing grand jury minutes in an unrelated case, but the indictment was dropped after Sirhan's sentencing, Pepper said.
"The state suppressed, destroyed and withheld a great deal of evidence," Pepper said in an interview Saturday. Sirhan's "counsel provided totally ineffective assistance and collaborated with the prosecution in violation of his 6th Amendment rights.
"The prosecution told the judge in chambers that we do not have foundation for some of our ballistics evidence, and the defense counsel immediately jumped in and said, don't worry about that, we will stipulate that all of the ballistics evidence is what you say it is," Pepper said.
Los Angeles County prosecutors couldn't immediately comment Saturday, a spokeswoman said.
Said Pepper: "This is one of the most egregious miscarriages of justice imaginable, and because it relates to the assassination of a man who would likely have been president of the United States, the feeling of sadness is irrepressible in these circumstances."
Pepper said he personally knew Kennedy and his family, and ran his campaign in the heavily Republican Westchester County in New York when Kennedy, a Democrat, successfully ran for the U.S. Senate in 1964.
Sirhan has Jordanian citizenship but never became a U.S. citizen, so if he were released from prison, he would be deemed an illegal immigrant and likely be deported to Jordan, where he has extended family, Pepper said.
In 1968, the 42-year-old Kennedy, younger brother of the assassinated President John F. Kennedy, was a leading contender for the Democratic presidential nomination against Vice President Hubert Humphrey and Sen. Eugene McCarthy.
On the night of his assassination, Kennedy had just appeared on live television in an Ambassador Hotel ballroom, where he had claimed victory over McCarthy in the California primary election. Moments later, he was fatally wounded in the hotel service pantry while on his way to a press conference set for a small banquet room just beyond the pantry. The shooting in the pantry was not captured by any cameras.
At Sirhan's 1969 trial, prosecutors argued Sirhan killed Kennedy because of statements the New York senator made about the United States sending fighter jets to aid Israel.
But in the court papers filed this week, Sirhan's attorneys dismissed that allegation as a "most speculative motive," without any sworn statements for substantiation.
Sirhan was the only person arrested in Robert Kennedy's assassination.
CNN's Brad Johnson contributed to this report.