SEATTLE, Oct. 18 — Law enforcement officials insist that radicals connected to the Symbionese Liberation Army, the Charles Manson family and other California militant groups were behind a bloody, ill-fated mass escape from the King County Jail.

One of the seven prisoners involved in the Sunday jailbreak, convicted murderer Artie Ray Baker, 26, masterminded the escape with the outside help of fellow radicals from California, police said Wednesday.

All the escapees and two accomplices were captured. One prisoner was killed by police gunfire.

Baker was a member of the revolutionary Wellsprings Communion, a group officials said maintains an isolated ranch in northern California’s Humboldt County.

Lawrence Edward Bailey, 30, arrested as one of the suspected accomplices in the jailbreak, also was a member of the Wellsprings Communion and before that was associated with the Charles Manson family, police said.

Reports filed by the U.S. Attorney’s office in federal court in Seattle described the Wellsprings Communion as an “offshoot” of the Symbionese Liberation Army, the group that kidnapped Patty Hearst in 1974.

Members of the group also had backgrounds in the Weather Underground, the Black Panthers and “other guerrilla families,” said the reports, prepared by Humboldt County authorities.

In his book “Helter Skelter” — on the Manson family’s brutal 1969 murder of actress Sharon Tate and four others — prosecutor Vincent Bugliosi said Bailey was one of those present when Manson ordered the killings.

Bailey was sought, unsuccessfully, as a witness in the Tate murder trial, Bugliosi said.

In 1971, Bailey was convicted along with three other Manson family members of trying to steal 140 guns from a Los Angeles sporting goods store. Police said the guns were to be used to free Manson.

Bailey, wounded by police bullets in Sunday’s jailbreak, gave his name as Jeffrey Pierce when he was arrested. The FBI discovered his true identity through his fingerprints.

The other accomplice, also wounded by police, gave his name as William Crest but was identified as William Dennis Dunne, 26. Police said they believed he was “connected” to Bailey and Baker.

Sunday’s jailbreak was accomplished when the prisoners obtained an automatic pistol and locked three guards in a cell. Authorities still don’t know how they got the gun.

The escapees had two getaway cars loaded with automatic weapons waiting, but the men were spotted by a passing police officer as they walked out onto the street.

Five prisoners and two wounded accomplices were captured after a series of high-speed chases and shootouts. A sixth prisoner was killed by gunfire. A police officer who suffered bullet wounds was hospitalized in serious condition.

The seventh prisoner, David Edward Warriner, 26, was captured on foot shortly before midnight Tuesday in the northern Washington woods, trying to cross into Canada. He was arrested by a fish and game agent.