The executive order will also argue that capital punishment is inherently unfair — applied more often to people of color and those with a mental disability, according to an administration source.

An $853,000 upgrade of the execution chamber at San Quentin was completed in 2010, but it has never been used. The last execution in California occurred Jan. 17, 2006, when Clarence Ray Allen, 76, was put to death. No executions have been carried out since.

A court-ordered moratorium on executions has been in place since February 2006, when a federal judge declared that California's lethal injection protocol was unconstitutional. A new execution protocol is under review, but Newsom's order will withdraw it.

Public opinion in California on capital punishment has shifted dramatically in the past few decades, with increasing numbers of people preferring the option of life without the possibility of parole to the death penalty in most cases.

However, in 2012 and 2016, California voters rejected ballot measures to abolish the death penalty. As they narrowly rejected Proposition 62 three years ago, voters narrowly passed a competing measure, Proposition 66, to expedite executions by shortening the appeals process. The California Supreme Court rejected part of that measure, while keeping most of it intact.

Newsom's action on the death penalty will no doubt place him in the national spotlight. What might have seemed avant-garde decades ago isn't anymore: The governors of Colorado, Oregon and Washington state have issued moratoriums on executions in recent years.

Eighteen other states and the District of Columbia have abolished the death penalty.