California Governor Gavin Newsom has moved to commute the death sentences of all 548 people on the state's death row, converting them to life in prison without the possibility of parole.

Newsom announced the decision on Thursday in an open letter to Californians, describing capital punishment as morally wrong. The move, if completed, would empty the largest death row in the Western Hemisphere and remove about a quarter of all death sentences in the United States.

Court review still required for most cases

The commutations are not all final yet. Under California's constitution, the governor cannot grant clemency to a person convicted of more than one felony without a recommendation from the state Supreme Court.

That condition applies to 382 of the 548 prisoners, about 70 per cent of those on death row. At least four of the court's seven justices must support the recommendation. Newsom has asked the court to return its recommendations by the end of 2026 so he can act before his term ends in January.

The remaining 166 commutations can take effect under the governor's own authority.

No execution in California since 2006

California has not carried out an execution since January 2006. Newsom imposed a moratorium on executions shortly after taking office in 2019, about two months into his first term.

The death penalty itself remains on the books in California, and prosecutors will still be able to seek it in future cases.

Reaction and timing

The announcement came two days after Democrats won control of both chambers of Congress in the midterm elections. Some prosecutors criticised the decision, saying they were not notified in advance.