California lawmakers vote to expand ban on death penalty for intellectually disabled people

A prison guard holds the arm of a handcuffed inmate carrying an orange bag through the cellblocks at San Quentin State Prison
A death row inmate is escorted back to his cell after spending time in the yard at San Quentin State Prison.
(Gary Coronado / Los Angeles Times)

More people convicted of murder may receive death penalty exemptions under a measure California lawmakers approved Friday that would expand whom the courts can classify as intellectually disabled.

Under the legislation, the death penalty could not be sought against defendants if health experts determined there was evidence of an intellectual disability that began during their “developmental period” — the time in a person’s life when their brain is developing — as defined by mental health diagnosis standards.

Current California law prohibits intellectually disabled defendants from being sentenced to death if mental health experts determine that their impairment was evident before they were 18 years old. This legislation removes that age threshold.

“All we’re really doing is updating the state of the science used to determine intellectual disabilities and developmental disabilities to what is currently being used,” said Assemblyman Mark Stone (D-Scotts Valley), who introduced the bill. “There are people who are sitting on death row who shouldn’t be there and don’t need to be there. That’s what we’re trying to rectify.”

The bill would also prohibit prosecutors in capital cases from adjusting the results of tests measuring a defendant’s intellectual ability based on their race, ethnicity, national origin or socioeconomic status.


The bill received strong support from death penalty opponents and was contested by the California District Attorneys Assn., which criticized the measure for creating “a vague and prejudicial loophole that would result in a miscarriage of justice for all murder victims and their loved ones.”

Assembly Bill 2512 will head to Gov. Gavin Newsom for his consideration. A staunch opponent to capital punishment, the Democratic governor just months after taking office placed a moratorium on the death penalty in California and ordered the dismantling of the execution chamber at San Quentin State Prison. The moratorium will expire as soon as Newsom leaves office, pushing decisions on capital punishment to his successor.

“The death penalty still technically exists,” Stone said. “So this policy is still very relevant and necessary.”

If the bill is signed into law, inmates on death row would have the right to petition the courts to assess whether they qualify as intellectually disabled under the new definition.

Retired Alameda County prosecutor Angela Backers, who handled death penalty cases for decades, said reputable mental health experts overwhelmingly agree that intellectual disabilities become evident before people turn 18 years old. Replacing the age threshold with a defendant’s age-indeterminate “developmental period” would allow defense attorneys to argue that their clients are intellectually disabled even if no signs of impairment surfaced until they were in their 30s, she said.

“They don’t want there to be a definition of intellectual disability. They want it to be all wishy-washy,” said Backers, co-chair of the California District Attorneys Assn. capital litigation committee. “All qualified experts agree that if you have an intellectual disability, it manifests itself before 18.”

In 2002, the U.S. Supreme Court ruled that it was cruel and unusual punishment to impose a death sentence on a person convicted of murder who had a mental disability.

In that ruling, Atkins vs. Virginia, the court relied on a definition of intellectual disability set by the American Psychiatric Assn., which said that the onset of such disabilities occurred before the age of 18.

California later adopted the Supreme Court’s definition for capital cases in state law, which stated that intellectual disability means “condition of significantly subaverage general intellectual functioning existing concurrently with deficits in adaptive behavior and manifested before 18 years of age,” when the brain is still developing.

The American Psychiatric Assn. has since changed its definition of intellectual disability, removing the age threshold and determining that the “developmental period” of a person should be left up to the discretion of physicians.

Stone said existing California law should be changed to reflect that new definition.

The assemblyman’s bill also prohibits prosecutors from arguing that Black and Latino people have less access than white people to adequate education, healthcare, nutrition and other essentials while growing up, and therefore may score lower on tests measuring potential intellectual disabilities, leading to a determination that results should be adjusted upward.

Backers, however, said that addresses a problem that does not exist.

“Where’s the proof of that?” she said. “Where is the proof where prosecutors inflate the IQs of people of color?”