California Governor Gavin Newsom has commuted the death sentences of all 548 people on death row in the state, changing them instead with life in prison.

“We can now let these offenders die in obscurity while we forever remember and honour the victims,” he said in a letter.

The decision to spare death row inmates is largely symbolic in a state that has not executed a prisoner since 2006, though experts say it could save millions of dollars in court costs each year. Only 13 inmates have been killed since voters reinstated the death penalty in 1978.

The decision comes as Newsom, the Democratic leader of the most populous US state, has been discussed as a possible 2028 contender for president.

Newsom, who is term limited, is winding down his final months in office. Fellow Democrat Xavier Becerra is projected to take over after the midterm elections on Tuesday.

Newsom explained in his letter that he is exercising his constitutional clemency authority to commute the sentences to life without the possibility of parole.

“After nearly 30 years in public office, I have come to understand the limits of what government can justly accomplish,” Newsom said. “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”.

California has historically had the largest population of death row inmates. Newsom had previously ordered a halt to the death penalty in the state in 2019.

Newsom, describing his decision as a difficult but “righteous action”, said that although many Californians feel that those who commit brutal crimes deserve to die, he has concluded that “the state cannot morally kill them”.

He said that by every measure, California’s system for administering the death penalty “is a failure”, and that it has not and cannot be fairly applied, resulting in the conviction of innocent people.

Life without the possibility of parole is the most severe punishment he can lawfully impose and that the state can ethically enforce, he said.

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