The charges against the former SLA guerrillas, who shot to fame in the early 1970s after kidnapping newspaper heiress Patricia Hearst, came after police arrested three of the suspects early on Wednesday: Emily Harris, her ex-husband Bill Harris and Michael Bortin.
Sacramento County District Attorney Jan Scully said first degree murder charges would also be filed against Kathleen Ann Soliah, who as Sara Jane Olson pleaded guilty in October to aiding and abetting a separate crime committed by the group, and James Kilgore, a former SLA member who remains at large.
"We all agree that after almost 27 years, justice has not been served," Scully told a news conference.
The murder charges stem from the April 21, 1975 shooting of Myrna Opsahl, 42, who was killed when the group raided the Crocker National Bank in Carmichael, California.
The arrests could resolve one of the last mysteries left by the Symbionese Liberation Army (SLA), a tiny group of gun-toting California political extremists.
They came just two days before Olson -- who lived for years in anonymity as the wife of a Minnesota doctor -- is due for sentencing in a separate 1975 SLA plot to bomb a police car.
Sacramento County Sheriff Lou Blanas said Olson, now out on bail, had turned herself in to authorities in Los Angeles Wednesday to face the new charge.
Olson faces 20 years to life in prison when she is sentenced on Friday, though her attorneys expect her to be released on parole in less than three years. It was not immediately clear how the murder charges would affect Olson's sentence or parole status in that case.
Scully said a conviction on the new murder charge could bring a sentence of life in prison.
The Crocker bank robbery drew nationwide attention because of the involvement of Hearst, who had been kidnapped by the SLA on Feb. 2, 1974.
Hearst, an heir to one of the United States' great newspaper fortunes, later re-emerged as a member of the radical group, taking the nomme-de-guerre "Tania" and participating in a number of SLA raids.
Hearst, who has been granted immunity in exchange for her testimony, said in her book "Every Secret Thing" that Olson, Emily Harris, Bortin and Kilgore went into the bank while she and others waited outside.
Hearst wrote that Harris, who served eight years in prison for the Hearst kidnapping, admitted shooting Opsahl, who was at the bank depositing collection money for her church.
In her book Hearst quoted Harris as brushing off the murder, saying: "Oh, she's dead, but it really doesn't matter. She was a bourgeois pig anyway."
Harris and Olson have denied involvement in the robbery and killing. Olson's brother Steven Soliah was tried in 1976 for the robbery and acquitted.
Olson as a fugitive for nearly a quarter century. In June 1999, FBI agents acting on a tip from "America's Most Wanted" captured her in St. Paul, Minn., where she was living as a mother, a doctor's wife and a community theater actress.
Emily Harris, now 55, was arrested in Los Angeles Wednesday morning. Her ex-husband Bill Harris was arrested in Oakland while Bortin, a longtime activist who is married to Olson's sister Josephine, was arrested at his home in Portland, Ore.
Scully said that following Olson's 1999 arrest authorities reviewed the case and decided to bring the charges based in part on new forensic evidence linking the slugs that killed Opsahl to a shotgun found at an SLA hideout in San Francisco.
"Fortunately... there is no statute of limitations for murders," Scully said. "Our community, the Opsahl family as well as the accused deserve their day in court."
The arrests follow a lengthy campaign by Myrna Opsahl's son Jon, now a California doctor, to compile evidence against the former SLA members. At a news conference Wednesday, he said he was gratified that these efforts had finally borne fruit.
"All I can really say is that our family has waited for 26 years for this day," Opsahl said. "There is just one other thing to say: that is, it's about time."
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