Senator Wiener’s Legislation to End Wrongful Convictions Resulting from Faulty Expert Witness Testimony Passes Senate Public Safety Committee

March 18, 2021

Sacramento - Today, Senator Scott Wiener (D-San Francisco)’s criminal justice reform legislation, Senate Bill 243, passed the Senate Public Safety Committee with a unanimous bipartisan vote. It will now head to the Senate Appropriations Committee.

SB 243 would amend the standards used for evaluating expert testimony and forensics in court pre- and post-conviction. Faulty forensic and scientific evidence, provided by expert witnesses, are the second most common reason that individuals are wrongfully convicted for crimes they did not commit. Today, courts have discretion over which expert testimony is admissible. Studies show that courts accept most forensic science and expert testimony without sufficient scrutiny, leaving significant room for imprecision and human error. This error leads to the high rate of wrongful convictions. Expert testimony that fails to rely on sound logic should not be considered expert testimony at all.

SB 243 clarifies that the definition of false testimony includes opinions based on flawed scientific research or outdated technology that is now unreliable or moot, and opinions about which a reasonable scientific dispute has emerged regarding its validity. SB 243 also clarifies that expert opinions that fail to use valid methodology, research, peer-reviewed studies, and scientifically sound data do not satisfy the requirements for admissible testimony.

This legislation additionally strengthens the grounds on which individuals wrongfully convicted of a crime based on unreliable expert testimony can seek post-conviction relief. This provision will help exonerate innocent people across California.

Recent studies from the National Academy of Science (NAS) and cognitive neuroscientist Dr. Itiel Dror have proven that fingerprint analysis, often part of expert witness testimony, is highly unreliable and subject to cognitive bias. The NAS also looked at what is known as the “CSI effect,” where jurors tend towards “unrealistic and preconceived notions about the availability and precision of forensic evidence in criminal trials” based on portrayals of expert witnesses in popular culture.

SB 243 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 must use evidence-based procedures when obtaining an 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. 

SB 243 is sponsored by the California Innocence Coalition, which is made up of the Northern California Innocence Project, Loyola Project for the Innocent, and the California Innocence Project.

“Faulty ‘expert’ witness testimony is one of the main reasons innocent people are sent to prison for crimes they did not commit,” said Senator Wiener. “That is an unacceptable miscarriage of justice. Even one innocent person in prison is too many. SB 243 will ensure that when expert witness testimony is given, the science behind it is reliable. This is an important criminal justice reform measure that will help many innocent people.”

“The Senate Public Safety Committee has time and again reminded us of how much they care about protecting the innocent,” said Melissa Dague O'Connell, Staff Attorney and Policy Liaison for the Northern California Innocence Project. “Today was no exception--the Committee's vote to move SB 243 forward recognizes how important it is for our criminal courts to stay lockstep with the advancements in and scrutiny of forensics and expert testimony to not just prevent wrongful convictions, but to intervene and restore justice when a wrongful conviction occurs.”