However, that hasn't been much of a problem for California since the state has not executed anyone since 2006 when Arnold Schwarzenegger was governor.
Newsom's executive order, in addition to the moratorium, would "withdraw the state's lethal injection protocol, and shut down the execution chamber at San Quentin State Prison", according to Buzzfeed.
He said he's campaigned "vigorously" for the last two ballot measures where voters rejected repealing the death penalty.
"The intentional killing of another person is wrong, and as governor, I will not oversee the execution of any individual", he plans to say.
California voters have, more than once, affirmed their desire for a death penalty.
"The moral leadership the governor is showing puts us in line with other countries and other states in terms of abolishing the death penalty", she said. Death row inmates are also much more likely to have a mental illness, brain damage or brain injury, or to be intellectually disabled.
A California Department of Corrections and Rehabilitation (CDCR) officer opens the door to San Quentin State Prison's death row on August 15, 2016 in San Quentin, California.
With 24 inmates on death row who have exhausted their appeals, Newsom in February said he feared California could potentially execute "more prisoners than any other state in modern history" if no action was taken. A judge is reviewing the latest execution protocol submitted by the state, and Newsom believed that its approval could come soon - clearing the way for executions to begin in California again. "It has discriminated against defendants who are mentally ill, black and brown, or can not afford expensive legal representation".
Newsom made the unusual decision through an executive order. A Pew Research Center poll completed past year found that a small majority of Americans support the death penalty but that those views were split by party.
The expected decision was derided by President Donald Trump Wednesday morning, who tweeted that Newsom was "defying voters" and that the "Friends and families of the always forgotten VICTIMS are not thrilled, and neither am I!"
This could create a challenge for Newsom, since his executive order would be denying the will of the California people.
Newsom may have a point to at least looking into the state's approach to the death penalty.
Newsom, a Democrat, told reporters earlier this month that he "never believed in the death penalty from a moral perspective", also citing ethical and economic concerns.
Most industrialized nations have abolished the death penalty, yet the US executes more people than any other democracy on the planet. "The disparities are really real and raw to me now, as I spend every week working on the issues of paroles and commutations and, substantively I see those disparities".