Gavin Newsom, California’s governor, commuted the death sentences of more than 500 people on the state’s death row on Thursday, a move that ensures they can never be executed under future administrations.

The Democrat’s mass commutation at the end of his term has converted all of the state’s death sentences to life without the possibility of parole, the largest clearing of any US death row in modern history.

The move comes after the failed execution of Christa Pike in Tennessee sparked global outrage and renewed calls for a nationwide pause on capital punishment.

His decision affects 529 men and 19 women who were sentenced to death in the state, making up the largest death row in the western hemisphere, the governor said in a letter announcing his decision.

“I take this action because I firmly believe that state-sanctioned killing is incompatible with California’s values, undermines the foundations of our legal system, and diminishes each of us,” he wrote. “I know we cannot execute people in our imperfect legal system and remain true to our core values, first among them justice and human decency.”

Newsom, considered a probable candidate for president in 2028, has long opposed the death penalty and issued a moratorium on executions in 2019. He also dismantled the state’s physical death row chamber in the infamous San Quentin prison, transferring people with death sentences to other facilities where they had more freedom of movement and access to programs – for some, a dramatic change after decades isolated in solitary cells.

The last execution in California was in 2006, but hundreds of people incarcerated in the state’s prisons have continued to live under death sentences, making California home to the largest death row population in the nation.

Newsom’s office noted on Thursday that of the 548 people sentenced to death, 220 of them had waited 15 years or more to be appointed habeas counsel, the legal representation they are entitled to access to fight their cases. And 139 people have waited 20 years or more for representation. If there were no moratorium in place, 45 people in the state are considered to have exhausted their appeals and would be immediately subject to execution.

“This decision is among the most difficult of my career, not because I doubt its necessity for our state but because I know its announcement may surface excruciating memories for victims’ families,” Newsom said. “I hold this painful truth along with the belief that this is a righteous action.”

The California supreme court will have to review and approve the clemency grants for cases where the individual was convicted of multiple felonies, Newsom said.

The announcement was praised by the American Civil Liberties Union and prominent advocates who oppose the death penalty, including Martin Luther King III, the eldest son of the civil rights icon, and Bryan Stevenson, an internationally renowned death penalty lawyer.

Jeanne Woodford, a former California prisons director who oversaw four executions, applauded Newsom in a statement, noting that more than 200 people nationwide had been exonerated after being sentenced to death: “As someone who has carried out executions in California, I am haunted by the fear that we will execute an innocent person.”

A relative of a victim killed by one man on California’s death row also spoke out in favor of the commutations. Jess Nichol is the sister of Polly Klaas, a 12-year-old killed in 1993 in a notorious case that paved the way for tough-on-crime laws. She said in a statement on Thursday that she used to support the execution of the man who killed her sister. “But over time I’ve realized that whether he’s executed has absolutely nothing to do with my recovery or with real public safety. The system tells survivors that execution matters to our healing. It doesn’t. It’s a distraction from what we actually need,” she said.

Governors of both parties have taken bold measures to oppose capital punishment over the years, including an Illinois Republican whocommuted all 167 death sentences in 2003 before leaving office. In 2024, North Carolina’s Democratic governor, Roy Cooper, commuted 15 death sentences in the state in his final day in office.

Support for the death penalty has beendeclining across the US, but Democrats at times have been reluctant to do mass commutations out of fear that Republicans will paint them as “soft on crime” politicians who sided with people convicted of brutal murders.

Newsom has supported criminal justice reform efforts, including changes to prioritize rehabilitative programs in prisons. But some advocates over the years have accused him of caving to political pressures on the issue, including when he has vetoed the release of high-profile prisoners even after they have been granted parole.

California is one of 27 states that still have the death penalty on the books.