Van Houten, 63, appeared before the parole board in a hearing at the California Institution for Women in Chino, the Los Angeles Times reported. The hearing was her 19th.
Van Houten, a high school cheerleader and homecoming queen in Monrovia, Calif., was two weeks away from her 20th birthday when she participated in the killing of the La Biancas on Aug. 9, 1969, at their home in Los Angeles. She was not involved in the killing a day earlier of Sharon Tate, the actress wife of director Roman Polanski, and four other people.
KABC-TV said prosecutors from Los Angeles County and relatives of the La Biancas were at the hearing and spoke against her release.
At a 2002 hearing, she accepted responsibility for the La Bianca killings, the Times said.
"I'm deeply ashamed of it," she told a parole board. "I take very seriously not just the murders but what made me make myself available to someone like Manson."
Van Houten, Manson and other followers involved in the killings were originally sentenced to death. They received life sentences after the U.S. Supreme Court overturned all existing capital punishment laws.
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