LOS ANGELES, Dec. 16 — Convicted murderer Leslie Van Houten, due for a second parole hearing next month, lost another round in her attempt to get out of jail when a California appeals court refused to overturn her conviction in the 1969 Tate-LaBianca murders.

In a 21-page response to her writ of habeus corpus, the 2nd Court of Appeal found “without merit” on Monday claims that the 31-year-old former follower of Charles Manson was given an ineffective defense during the third trial and that the court erred by dismissing a juror and replacing him with an alternate.

Also rejected were her claims that the court erred by admitting in evidence gruesome photographs of the murder victims and by admitting details of the crime conspiracy prior to the time she allegedly joined the conspiracy.

Her initial conviction with Manson and two other women was overturned in 1976. A second trial resulted in a hung jury and the third in her reconviction of first-degree murder.

Imprisoned at the California Institution for Women at Frontera, she has said she hopes to be released after her parole hearing and that she believes she is totally rehabilitated.

Last January, Ms. Van Houten was refused parole in spite of good reports from psychologists and prison staff members.

Ruth Rushen, chairman of that parole board, said then: “Society has no defense … in this type of crime, except to isolate the offender.”

Earlier this year, the board refused to grant parole to Manson and the others convicted in the Tate-LaBianca murders — Susan Atkins, Patricia Krenwinkel and Charles “Tex” Watson.