A federal judge ruled on Wednesday that California's death penalty is unconstitutional, saying the system is arbitrary and unfair, and that because the process is plagued with lengthy and unpredictable delays it amounts to cruel and unusual punishment.

The ruling by U.S. District Court Judge Cormac J. Carney, a conservative Republican judge appointed by President George W. Bush, is a major victory for California's opponents of capital punishment in the state, and comes after a similar decision that halted executions in the state eight years ago.

In a case brought by a death row inmate against the warden of San Quentin state prison, Carney called the death penalty an empty promise that violates the Eighth Amendment's protection against cruel and unusual punishment.

"Inordinate and unpredictable delay has resulted in a death penalty system in which very few of the hundreds of individuals sentenced to death have been, or even will be, executed by the State," the ruling read.

A death penalty appeal can last decades, Carney said, resulting in most condemned inmates dying of natural causes.

Carney wrote that since the current death penalty system was adopted by California voters 35 years ago, more than 900 people have been sentenced to death, but only 13 have been executed.

"As for the random few for whom execution does become a reality, they will have languished for so long on Death Row that their execution will serve no retributive or deterrent purpose and will be arbitrary," the judge stated.

Gil Garcetti, a former Los Angeles County district attorney, who has become an anti-death-penalty activist, called the ruling "truly historic."

"It further proves that the death penalty is broken beyond repair," he said, calling for capital punishment to be replaced "with life in prison without the possibility of parole."

Carney's ruling came in a legal petition brought by Ernest Dewayne Jones, sentenced to die in 1994 after being convicted of raping and murdering his girlfriend's mother.

Jones remains on death row "with complete uncertainty as to when, or even whether," his execution will come, the judge wrote, adding, "Mr. Jones is not alone."

The governor or state attorney general, both of whom oppose the death penalty, could appeal Carney’s ruling.

For now, Jones will likely remain on death row.

Matt Cherry, executive director of Death Penalty Focus, a group opposed to the death penalty, told Al Jazeera the ruling sets a clear precedent.

“We think this is a very historic ruling. It’s the first time that a federal court has found California’s death penalty to be unconstitutional, and it’s also the first time that any court has found a state’s death penalty to be unconstitutional because it’s arbitrary and unfair,” he said, adding that the state has more than 700 people on death row.

“Our hope is that the state replaces the death penalty with life without parole and shuts down its death row,” Cherry said. “Currently life without parole is the ultimate punishment in California, except for the death penalty.”

Carney noted that “arbitrary factors” such as the manner in which paperwork is handled are what “determine whether an individual will actually be executed.”

Another federal judge put California's death penalty on hold in 2006 when he ruled that the state's lethal injection procedures needed overhaul.

The judge found that the state's procedures created too much risk that an inmate would suffer extreme pain while being executed. At that time, lethal injections were carried out in San Quentin's old gas chamber, which the judge found too cramped, too dark and too old for prison staff to properly administer execution drugs.

Since then, the California Department of Corrections and Rehabilitation has built a new execution chamber on the grounds of San Quentin state prison in the Bay Area, and made a number of changes to its procedures to address the judge's concerns.

A new federal judge has taken over the case and has not ruled on whether those changes are enough to restart executions.

Additionally, the corrections department is drafting a new set of regulations for administering lethal injections. No executions can take place until the new rules are formally adopted.

The California decision issued Wednesday comes after several states have botched their executions as a result of using chemical combinations that had never before been used to execute a prisoner.

Cherry said he hopes this will be the tipping point for other states to usher out their death penalties.

“I would hope other states would act to end their lethal injections because of their cruelty,” he said. “However, we have yet to see any of the states with the most botched executions try to do anything.”

Al Jazeera and The Associated Press. Dexter Mullins contributed to this report.