A state judge in Santa Monica, Calif., says the mental state of Marlon Brando's daughter, Cheyenne, precludes her from coming back from Tahiti to testify in her half-brother's murder trial.

Christian Brando is accused of killing Cheyenne's lover, Dag Drollet, last summer.Prosecutors who had been trying to bring Cheyenne back from Tahiti to testify had asked Rudof to intervene with French authorities in Tahiti to have her returned.

The judge wrote that prosecutors had provided him with "insufficient information to permit this court to further endanger what appears to be a fragile mental condition and attempt to have Miss Brando returned."

Cheyenne, 20, potentially the prosecution's star witness, spent the evening of the shooting with Christian and made statements to police that the killing was premeditated.

Days after the slaying, Cheyenne returned to her home in Tahiti and gave birth to Drollet's child. She has been hospitalized several times and twice has attempted to kill herself.

Sandi Gibbons, a spokeswoman for the District Attorney's Office, said prosecutors will not challenge Rudof's decision unless Cheyenne's condition significantly improves in the roughly three weeks before the trial.