Sara Jane Moore, 89, was taken into custody at New York City's JFK Airport Saturday by federal authorities after she flew back from a trip to Israel.
Authorities told Fox News that Moore failed to tell her parole officer about the international trip, violating the terms of the lifetime parole she was granted in 2007 for having served 32 years of a life sentence at the Federal Correctional Institution in Dublin, California.
Moore supposedly fell ill while in Israel, causing her to stay in the country longer than she had anticipated, a source told the cable news network.
Following Moore's arrest, she was expected to appear before a judge and then meet with a parole commission this week.
Prison records revealed Tuesday that Moore is still being held at the Metropolitan Detention Center in Brooklyn, New York.
Moore, a self-styled radical, became the second woman ever to attempt to assassinate a sitting US president on September 22, 1975, when she tried to kill then-President Gerald Ford while he was visiting San Francisco, where she lived at the time.
She said she wanted his death to trigger a new, violent revolution in the country in the aftermath of the Vietnam War.
In early 1974, the single mother, who was also operating as an FBI informant at the time, volunteered to be the Symbionese Liberation Army's (SLA) bookkeeper.
The SLA was an American left-wing militant organization that operated between 1973 and 1975 and was behind a string of bizarre crimes in Northern California including two murders and bank robberies. The group famously kidnapped newspaper magnet Randolph Hearst's daughter, Patricia Hearst in 1975.
The FBI ultimately cut her loose following interviews she did in which she revealed she was an informant - an attempt for her to establish radical credentials.
Four months after being cut loose by the FBI, Moore stood across the street from the St. Francis Hotel with other onlookers, waiting for Ford to exit the hotel.
When Ford moved towards his waiting car, Moore pulled a .38 handgun out of her handbag and fired it at the president, sending Secret Service into motion and hustling Ford into his car, which then drove off to safety.
Moore, then 45 years old, only missed hitting the president because her aim was thrown off when disabled former Marine Oliver Sipple, who was standing near her, grabbed her arm.
Photos from the dramatic incident reveal the moment when Ford winced and ducked after hearing the gunshot and when Sipple reached out and held Moore's arm as others nearby ran away and authorities rushed towards her.
Moore was taken into custody and pleaded guilty to attempting to assassinate Ford in January 1976. She was sentenced to life in prison.
At her sentencing hearing, Moore expressed some remorse for attempting to the kill the 38th president.
'Am I sorry I tried? Yes and no,' she was reported as having said. 'Yes, because it accomplished little except to throw away the rest of my life. And, no, I’m not sorry I tried . . . because at the time it seemed a correct expression of my anger.'
According to a 1975 New York Times report about the incident, police had actually confiscated Moore's .44-caliber gun, which she had been planning to use on Ford.
Police at the time claimed she had told them that if she had still had her .44, she would've 'caught him.'
Instead, she had been forced to go obtain and use the .37-caliber weapon that failed to hit her mark.
On December 31, 2007, she was released from prison due to an old federal law that mandated parole for federal inmates who have served out at least 30 years of their life sentences without getting into trouble, SF Gate reported. The parole loophole was closed in 1987.
During a 2009 interview on TODAY, Moore was quoted as explaining the assassination attempt by reminding viewers that 'it was a time that people don’t remember.'
'You know we had a war . . . the Vietnam War, you became, I became, immersed in it,' she said. 'We were saying the country needed to change. The only way it was going to change was a violent revolution. I genuinely thought that [shooting Ford] might trigger that new revolution in this country.'
The last US troops were withdrawn from Vietnam on March 29, 1973.
Moore also revealed during the interview about her decision to try to kill Ford that 'if I hadn’t done it, someone else would’ve…That was the tenor of the time. There was more talk about it than people realize'.
Three weeks before Moore attempted to assassinate Ford, Charles Manson acolyte Lynette 'Squeaky' Fromme became the first woman to try to kill a sitting US president when she made an assassination attempt against Ford during his appearance in Sacramento, California.
Fromme, who pulled out her handgun, but didn't manage to squeeze off a shot, was also given a life sentence. She was released on parole in August 2009, after serving 34 years.