California Gov. Gavin Newsom on Tuesday blocked parole for Charles Manson follower Leslie Van Houten, reversing a panel's recommendation that she be freed after spending a half-century in prison.

Newsom said in his parole review that Van Houten, 72, "currently poses an unreasonable danger to society if released from prison at this time,"

It was the fifth time that a California governor has rejected her release.

Van Houten is serving a life sentence for helping Manson and others kill Los Angeles grocer Leno LaBianca and his wife, Rosemary, in August 1969. Van Houten was 19 when she and other cult members fatally stabbed the LaBiancas and smeared the couple's blood on the walls.

In his rejection letter, Newsom noted that Van Houten had undergone therapy, earned educational degrees and taken self-help classes in prison and had shown "increased maturity and rehabilitation."

But Van Houten also has "gaps in insight" that continue to make her a danger to society, Newsom said.

Van Houten has had 21 parole hearings since 1982. Most parole boards denied her bid for freedom. But five panels have recommended her release since 2016, saying she had expressed remorse and was no longer a threat to public safety.