DELANO – A Bay Area native who previously allegedly killed the co-founder of a notorious skinhead group in Orange County was killed in his jail cell, authorities announced Friday.

Jacob Kober, 35, was stabbed multiple times in his cell at Kern Valley State Prison on Thursday, authorities said. His cellmate, 39-year-old Matthew Perez, also suffered injuries consistent with a “prison-made weapon,” in keeping with a news release from the California Department of Corrections and Rehabilitation.

Authorities said only Kober and Perez were within the cell on the time of the murder.

Known as an area methamphetamine and marijuana dealer within the Livermore area in 2015, Kober was serving a life sentence for killing a longtime friend on the fourth hole of a golf course. But in 2018, he was again implicated in murder, this time for a jail stabbing that had repercussions throughout the state's prison system.

The victim was 48-year-old Devlin Stringfellow, an Orange County native and co-founder of the skinhead gang Public Enemy Number One, or PENI. Prosecutors now say his murder was ordered by an Aryan Brotherhood member named William Sylvester, who was convicted of organized crime last April and now faces a life sentence.

Prosecutors say Stringfellow's 2018 murder was a typical Aryan Brotherhood attack. It happened during a training exercise at California State Prison in Sacramento. Someone hit Stringfellow on the pinnacle with a rock to stun him, then Kober and 49-year-old Stephen Dunckhurst allegedly stabbed him, in keeping with testimony at a trial of Sylvester and two other Aryan Brotherhood members.

While awaiting trial, Sylvester reportedly boasted to other co-defendants about ordering Stringfellow's death. Another PENI co-founder, Donald “Popeye” Mazza, later agreed to testify for the federal government, partly due to his grief over Stringfellow's death, Mazza said during his testimony on the organized crime trial.

Kober was sentenced to life in prison in 2015 for killing his friend Kenneth Robert Ogden, 28, amid mounting tensions between the 2 men. Kober had previously accused his girlfriend of getting sex with Ogden, and in addition they had a dispute over money, authorities said on the time. Kober made his money selling drugs and lived just yards from the fourth hole of a close-by golf course, where Ogden's body was found, court records show.

According to authorities, Perez was serving a jail sentence for assault with a firearm and gang activity.

Originally published: September 20, 2024 at 3:25 p.m.

FRESNO — In the most recent twist in an already widespread case against the Aryan Brotherhood, prosecutors have filed latest murder and conspiracy charges against a person who has spent most of his adult life behind bars and is already serving concurrent life sentences in federal and state prisons.

In an organized crime indictment unsealed this week, longtime California inmate John Stinson was charged with two counts of conspiracy to commit murder and EDD fraud, joining an inventory of 20 alleged Aryan Brotherhood members and associates accused of a complete of seven murders and multiple murder conspiracies. Combined with a related indictment in federal court in Sacramento, this latest case means federal authorities have linked the prison gang to at the least 14 murders since 2019, including two separate double murders in Southern California and 10 prison stabbings.

For Stinson, this charge is a way of déjà vu. He was convicted in 2007 of conspiring with high-ranking members of the Aryan Brotherhood for 4 murders and a number of other attempted murders, including the infamous murder of Richard Barnes in 1986. Barnes was reportedly killed because his son agreed to testify against the gang.

According to media reports, he has been behind bars since 1981, when he was convicted in Los Angeles County of murdering a Long Beach-area heroin dealer named Alfredo Armijo. As a results of those convictions, Stinson is already serving life sentences in each California and federal prisons.

According to court records, Stinson was transferred from Solano State Prison in Vacaville to the Fresno County Jail due to a federal prison sentence.

Another latest defendant, Andrew “Misfit” Collins, is accused of participating in considered one of the murder plots alongside Stinson. Prosecutors also added a previously uncharged murder count, alleging that gang members Francis Clement and Jason “Beaver” Weaver murdered a person on February 22, 2022. Weaver can also be accused of killing Hugo “Yogi” Pinell, a member of the San Quentin Six, together with Waylon Pitchford in a 2015 stabbing attack at Represa's New Folsom Prison.

The charges come weeks after a Sacramento jury convicted three members of the Aryan Brotherhood of conspiracy to murder and other crimes, including smuggling drugs into prison. Much of the evidence was based on a wiretap of smuggled prison cellphones.