Senator Wiener’s Legislation to End Wrongful Convictions Due to Faulty Expert Witness Testimony Signed into Law

October 6, 2022

SACRAMENTO - Governor Gavin Newsom signed into law Senator Scott Wiener’s (D-San Francisco) Senate Bill 467. SB 467, the End Wrongful Convictions Act, amends the standards used for evaluating expert testimony and forensics in court post-conviction. This law will take effect on January 1, 2023..

“The End Wrongful Convictions Act will get innocent people out of prison,” said Senator Wiener. “When anyone spends even a day in prison for a crime they did not commit, it’s a terrible miscarriage of justice. Now, we’ll have more tools to help exonerate anyone wrongfully convicted on the basis of outdated or flawed science. This is a victory for the integrity of our criminal justice system.”

“Senator Wiener continues to be a champion for the innocent by authoring and advocating for laws that both help the wrongfully convicted regain their freedom and prevent wrongful convictions from happening in the first place,” said Melissa O’Connell of the California Innocence Coalition.

SB 467 clarifies that the definition of false testimony includes expert opinions undermined by the state of scientific knowledge  and creates a path for the wrongfully convicted to obtain justice when their convictions were based on expert opinions about which a significant dispute has emerged or further developed regarding its validity.  The California Supreme Court has long recognized that “[l]ay jurors tend to give considerable weight to ‘scientific’ evidence when presented by ‘experts’ with impressive credentials'' but emphasized “scientific proof may in some instances assume a posture of mystic infallibility in the eyes of a jury . . .”(People v. Kelly (1976) 17 Cal.3d 24, 31-32.)

Unreliable forensic science remains a leading cause of wrongful convictions, occurring in 45% of DNA exoneration cases nationwide, 24% of all exonerations in the nation and 15% of the California exoneration cases known since 1989. In these cases, “expert”  testimony that was either flawed or false forensic science,  or relied on scientific methods that are widely debated within the scientific community provided critical evidence leading to the conviction. In California, 70% of these innocent men and women were given life sentences; one was sentenced to death.

SB 467 is part of a larger slate of the California Innocence Coalition’s reform bills. Previously, Senator Wiener authored SB 923, which ensures that law enforcement use evidence-based procedures when obtaining eyewitness identification. Eyewitness misidentification is a leading contributor to wrongful convictions proven with DNA evidence. Before SB 923 was signed into law, California had no statewide best practices for eyewitness identification and there were no evidence-based standards in place. With the passage of SB 467, California takes a giant step forward to address concerns set forth by the scientific community itself as well as to allow our courts to remain lockstep with advancements in science

SB 467 is sponsored by the California Innocence Coalition, which includes the Northern California Innocence Project, the California Innocence Project and the Loyola Project for the Innocent.

California Innocence Coalition Case Contacts

Jasmin Harris –

Melissa O’Connell—