LOS ANGELES, Jun. 10 – A key prosecution witness in the trial that convicted Robert Beausoleil of murdering musician Gary Hinman has signed an affidavit saying that she testified falsely and under pressure from authorities, the court has been told.

Beausoleil, 22, made the disclosure Tuesday acting as his own attorney in arguments for a new trial and reduction of the death sentence imposed on him.

Elsie Brunner, mother of Mary Brunner, a former member of Charles Manson’s clan who testified against Beausoleil, told the court she discussed the affidavit with her daughter last week in Eau Clair, Wis. Mrs. Brunner said her daughter told her she “could have made it worse” for Manson in her testimony in court and before a grand jury.

Mrs. Brunner testified after being promised immunity. In return for complete cooperation with the district attorney’s office in court all proceedings concerning the Hinman murder.

In her affidavit she said she was “coerced” into testifying by the district attorney’s office because she feared her 2-year-old boy, fathered by Manson, might be taken from her.