A California law that took effect last year is encouraging prosecutors, attorneys and judges to better scrutinize potentially flawed or outdated science and disputed expert testimony to avoid wrongful incarcerations, according to the law’s supporters.
Senate Bill 467, authored by state Sen. Scott Wiener (D-San Francisco), expands the meaning of “false evidence” so that incarcerated individuals are better able to file habeas corpus petitions when there is a reasonable basis on whether questionable science was key to proving guilt.
Writs of habeas corpus allow prisoners to challenge whether their detention is lawful before a civil court.
Jasmin Harris, policy representative for the California Innocence Coalition, which includes the Loyola Law School Project for the Innocent and Los Angeles Innocence Project, said one of the goals of the legislation was to give innocent people now serving prison sentences an opportunity to challenge their convictions whenever faulty scientific testimony or junk science was central to their criminal justice proceedings.
A second goal of the new law is to affect ongoing court proceedings, Harris told the Southern California Record in an email.
“The hope is that practitioners and the courts will use more stringent judgment when considering what to use and what to allow in,” she said. “The second prong is tough to measure, but our hope is that there is some forethought for the practitioners and the courts when making decisions on which experts to use and allow in.”
The law spells out how inmates’ attorneys can dispute a previous medical, scientific or forensic report or testimony using peer-reviewed studies or credible expert testimony based on new scientific data.
“Studies have found that most expert testimony regarding forensic science is accepted without demonstrating the precision of its methods, its potential limitations or the possibility for human error,” Sen. Wiener said in comments about the legislation. “Unreliable forensic science remains a leading cause of wrongful convictions, occurring in 45% of DNA exoneration cases, 24% of all exonerations in the nation and 15% of the California exoneration cases known since 1989.”
Another problem that can lead to wrongful convictions has to do with “CSI effect,” in which jurors have preconceived notions about the supposed infallibility of forensic evidence and testimony based on what they’ve seen in television programs, according to a report by the National Academy of Science.
A legislative analysis of SB 467 points out that traditional scientific studies about microscopic hair comparisons and fingerprints are no longer considered foolproof in the criminal justice system.
“The Federal Bureau of Investigation (FBI) used to testify that ‘with 100% scientific certainty’ that fingerprints or microscopic hairs could be a conclusive match,” the analysis states. “Now, given scrutiny within the community of these scientific practices, they do not make these statements because they have been wrong before.”
Further reforms are needed, but they must be paired with education, according to Harris, adding that courts need to assume more of a gatekeeping role to root out flawed science during trials.
“We must also insist on judicial education around the different forensic sciences, including the forensics that only have a perceived scientific value, so the courts are armed with the knowledge they need to make these important decisions,” she said.
There is an inherent tension between courts, which often focus on past precedents, and the scientific method, in which conclusions can change based on new research, according to Harris.
“Generally speaking, science is constantly evolving and moving forward,” she said. “It's the nature of science. The law was built to look back and build on itself. This inherent disconnect harms innocent people.”