SACRAMENTO, Jan. 23 – The federal judge who sentenced Lynette Fromme to life in prison for attempting to kill President Ford has refused to disqualify himself from the trial of her roommate, Sandra Good.

U.S. District Court Judge Thomas MacBride also ruled Thursday that Miss Good and codefendant Susan Murphy can act as their own lawyers in their trial on charges of conspiracy to write threatening letters.

Miss Good and Miss Fromme are followers of convicted mass murderer Charles Manson. Miss Murphy is a former roommate of the other women, but says she never met Manson and does not consider herself among his followers.

MacBride rejected Miss Good’s complaint that he should not preside at her trial because he was afraid she would physically harm him if she goes free.

And, the judge said, it was only a slip of the tongue that caused him to refer to Miss Good as “Miss Fromme” last week. Miss Good had cited that as a proof of his bias.

Miss Good and Miss Murphy are charged with conspriing to send 171 letters to business and government leaders threatening that they would be killed or harmed if they didn’t stop polluting the environment. Miss Good is also charged with making similar threats in four telephone interviews.

The 31-year-old Miss Good tried to contest MacBride’s ruling that he wouldn’t disqualify himself.

“I have ruled and that’s it. There will be no further argument on that question,” MacBride said.

He then asked if she was ready for a ruling on her motion to act as her own attorney

“Oh, so you’re the judge in this case. I didn’t really expect that you’d proceed in this case. I think your prejudice is obvious,” she replied.

MacBride granted her permission to act as her own lawyer and agreed to her request that William Shubb, a former deputy U.S. attorney, serve as cocounsel.

“If you dismiss him, I will not appoint another,” MacBride said.

He agreed to let Miss Murphy, 33, act as her own lawyer and appointed Sacramento attorney John Moulds as her cocounsel. Miss Murphy did not ask that MacBride disqualify himself, but Moulds said he might make such a motion later.

MacBride ordered both women to return to court next Tuesday and enter pleas.

Miss Good is held on $100,000 bail. Miss Murphy is free without bail.