SANTA ANA ( — A judge in Orange County ruled Friday that death penalty will not be an option in the sentencing of mass shooter Scott Dekraai.

Judge Thomas M. Goethals opted to remove the death penalty as a sentencing option for 47-year-old Dekraai, who pleaded guilty to killing eight people in a 2011 shooting rampage at a Seal Beach salon, over the Orange County Sheriff’s Department’s use of jailhouse informants.

READ MORE: WeHo Residents Preparing For New 'Supreme' Location

Defense lawyers had argued that repeated failures by sheriff’s authorities to reveal records related to informants show the agency can’t be trusted to turn over evidence favoring their client.

The ruling comes amid an uproar over the use of jailhouse informants in this Southern California county. The U.S. Department of Justice and state Attorney General’s office are each investigating the county’s practices and prosecutors have seen at least four murder cases upended by the scandal.

Dekraai has pleaded guilty to killing his hairstylist ex-wife Michelle Fournier before turning his gun on her co-workers and others at the salon where she worked in Seal Beach. He was arrested minutes after the rampage that left eight dead and one wounded.

Dekraai’s lawyer Scott Sanders began asking questions about the use of jailhouse informants after noticing the same snitch had chatted up Dekraai and another one of his clients. Authorities can use informants but can’t have them deliberately elicit information from defendants once they are represented by lawyers.

After finding sheriff’s authorities lied or withheld snitch-related information, Goethals yanked the district attorney’s office off Dekraai’s case in 2015. He also ordered authorities to release jailhouse records. Documents have been released bit by bit.

“The concealment has gone on forever,” Sanders said during closing arguments last week. “When people don’t tell the truth, we really have no sense of where it stops.”

READ MORE: Stanford Completes Season Sweep Of No. 15 USC, 64-61

Deputy Attorney General Michael T. Murphy said misconduct may have occurred in the case but Dekraai needs to be punished for his crimes. He said the government holds no documents that will prove relevant to penalty hearings focused on the killings and Dekraai’s comments immediately after his arrest.

“The defense has failed to show that any actions of the government in the past have eliminated the possibility of getting a fair penalty trial,” Murphy told the court.

Orange County sheriff’s officials declined to comment before the ruling.

Goethals has said he will not impose punitive measures on authorities but rather seek to determine whether a remedy is required to ensure justice is

Robert Dunham, executive director of the Death Penalty Information Center in Washington, said cases where prosecutors are barred from pursuing capital punishment are rare and any decision by Goethals will likely be appealed.

“This case is notable and is being watched because of the severity of the offense, but it is also notable and being watched because of the unparalleled nature of the government misconduct,” he said.

MORE NEWS: Exclusive: 21-Year-Old Homeless Man Charged In Yet Another Metro Bus Stop Attack, Victim Speaks Out

(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)