Updated

A federal magistrate has ruled that a California prisoner serving life without parole for a triple murder should be freed because his defense lawyer provided in incompetent representation at his trial.

U.S. Magistrate Michael Seng ruled this week that George Souliotes, 72, should be released because his lawyer failed to adequately defend him in a "fundamentally unfair" trial, according to the Los Angeles Times.

In his 93-page ruling, Seng criticized the "unprofessional" performance of Souliotes' attorney, who promised jurors he would call certain witnesses but then failed to summon them without explanation.

Seng's decision follows a ruling last year that Souliotes had proved "actual innocence" and no reasonable juror would convict him based on the current evidence.

The Greek immigrant has been in prison for 16 years for the killings of a mother and her two young children, who died when a fire erupted in a Modesto house he owned in 1997.

Prosecutors, who had sought the death penalty for Souliotes, now admit they cannot prove the house fire was deliberately set.

Souliotes' lawyers filed a motion Friday asking the magistrate to release him immediately, citing the prisoner's poor health. They say their client has no prior criminal record, no record of prison discipline and poses no threat to society.

But state Attorney General Kamala Harris has fought to keep Souliotes in prison. Deputy Attorney General Kathleen McKenna said Friday she disagrees with the magistrate's findings and plans to object.

Souliotes' sister, Aleka Pantazis, said she's worried her brother might die in prison before his release.

"The most courageous thing for the state to do is to realize that it has been a mistake," said Pantazis, 65, of Glendale. "They have to let it go."