A California senator introduced a bill last week that seeks to change the legal standard for expert witness testimony, specifically in relation to forensic evidence.
Senator Scott Wiener’s (D-San Francisco) Senate Bill 243, also known as The End Wrongful Convictions Act, would expand the definition of false evidence to include expert forensic opinions that are outdated and have been proven invalid within the expert’s own scientific community. Bite mark evidence is perhaps the most famed example of an outdated method, previously used in many cases but concluded to be scientifically invalid by the 2016 PCAST report.
“Problematic forensic science remains a leading cause of wrongful convictions, occurring in nearly half (45%) of DNA exoneration cases and one-quarter (24%) of all exonerations in the United States. Research shows that experts whose opinions led to wrongful convictions either used forensic science that was flawed or scientific methods that are widely questioned within the scientific community,” the Northern California Innocence Project said in a statement.
SB 243 seeks to ensure that all expert testimony, as well as the underlying materials used to form said opinions, have a reliable foundation, proper methodology and sound logic.
"For our justice system to work, we need to convict the guilty and not convict the innocent. Sadly, we convict far too many innocent people based on faulty expert scientific testimony. We’re pursuing first-in-the-nation legislation to put an end to this problem by requiring significantly more scrutiny of scientific testimony to ensure that it’s actually valid,” Weiner said in a statement.
The senator proposed a previous version of this bill, SB 938, in February 2020, but it died in committee due to the COVID-19-induced shortened 2020 legislative calendar. Both SB 243 and its predecessor are sponsored by the California Innocence Coalition.
Weiner has been actively involved in criminal justice reform throughout his political career. Previously, he authored SB 923, which seeks to ensure that law enforcement uses evidence-based procedures for 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 may be acted upon on or after February 21.