Patty Hearst's former comrades plead guilty to 1975 murder

Four former members of the Symbionese Liberation Army (SLA), the Californian guerrilla group that kidnapped Patty Hearst, pleaded guilty yesterday rather than face trial for the last outstanding crime of their days of political violence – the murder of a disabled housewife shot dead during a 1975 bank robbery outside Sacramento.

Under a deal worked out with prosecutors, who revived the case years after it had been abandoned because it was deemed to be unsolvable, the four defendants pleaded guilty to second-degree murder in exchange for assurances that they would serve no more than six to eight years in prison. They, as well as a fifth defendant who has been on the run since the mid-1970s, had been charged with first-degree murder and faced possible life sentences if convicted at trial.

The plea deal also meant that Patty Hearst – the newspaper heiress who was first kidnapped by the gang, then joined in their activities – would not be forced to retell the story of the bank robbery under oath.

Ms Hearst, who repudiated her association with the other SLA members after serving two years behind bars and who has since received a presidential pardon, has insisted for years that it was SLA member Emily Harris who pulled the trigger and who killed 41-year-old Myrna Opsahl at the Crocker National Bank in Carmichael.

On two occasions, prosecutors attempted to mount a trial based on Ms Hearst's testimony but gave up because she was deemed an unreliable witness and they could find no corroborating evidence for her story.

That attitude changed three years ago when police tracked down a late recruit to the SLA, Kathleen Soliah, who had been living incognito in Minnesota for years under the name Sara Jane Olson.

Last year, Ms Olson pleaded guilty in connection with the attempted bombing of two police cars in Los Angeles and began serving a sentence that is expected to last at least 14 years. The Opsahl murder case was revived shortly afterwards, and Ms Olson was arrested again, with Harris, Harris's former husband, Bill Harris, and another group member, called Michael Bortin.

The Harrises and Mr Bortin had all served out long sentences for other crimes for which the SLA was responsible and assumed they could return to normal lives.

It is not clear whether prosecutors have genuinely unearthed new evidence in the Opsahl case, or if they have merely taken advantage of a more gung-ho criminal justice climate to pressure the defendants into admissions of guilt. Because of the plea bargain, the identity of the killer in the Opsahl murder remains as elusive as ever.