Sweeping claims made in courtrooms about fingerprints, ballistics, bite marks and other forensic evidence often have little or no basis in science, according to a landmark report released Wednesday by the nation's leading science body.
The National Academy of Sciences report called for a wholesale overhaul of the crime lab system, which has become increasingly crucial to American jurisprudence.
Many experts said the report could have a broad impact on crime labs and the courts, ushering in changes at least as significant as those generated by the advent of DNA evidence two decades ago. But the substantial reforms would require years of planning and major federal funding.
In the meantime, the findings are expected to unleash a flood of new legal challenges by defense attorneys.
"This is a major turning point in the history of forensic science in America," said Barry Scheck, co-founder of the Innocence Project, an organization dedicated to exonerating the wrongfully convicted. He said the findings would immediately lead to court challenges.
"If this report does not result in real change, when will it ever happen?" Scheck asked.
The Los Angeles County Public Defender's office plans to use the National Academy report to file challenges on the admissibility of fingerprint evidence and is reviewing cases in which fingerprints played a primary role in convictions, officials said.
Separately, the Los Angeles Police Department has been reviewing 1,000 fingerprint cases after discovering that two people were wrongfully accused because of faulty fingerprint analyses.
The academy, the preeminent science advisor to the federal government, found a system in disarray: labs that are underfunded and beholden to law enforcement and that lack independent oversight and consistent standards.
The report concludes that the deficiencies pose "a continuing and serious threat to the quality and credibility of forensic science practice," imperiling efforts to protect society from criminals and shield innocent people from convictions.
With the notable exception of DNA evidence, the report says that many forensic methods have never been shown to consistently and reliably connect crime scene evidence to specific people or sources.
"The simple reality is that the interpretation of forensic evidence is not always based on scientific studies to determine its validity," the report says.
For example, frequent claims that fingerprint analysis had a zero error rate are "not scientifically plausible," the report said. The scientific basis for bite mark evidence is called "insufficient to conclude that bite mark comparisons can result in a conclusive match."
Recent cases of CSI gone awry have underscored the report's urgency. In the cases of the 232 people exonerated by DNA evidence, more than half involved faulty or invalidated forensic science, according to the Innocence Project.
Margaret Berger, a professor at Brooklyn Law School and a member of the panel, explained: "We're not saying all these disciplines are useless. We're saying there is a lot of work that needs to be done."
Said U.S. Court of Appeals Judge Harry Edwards, co-chairman of the panel: "There are a lot of people who are concerned, and they should be concerned. Forensic science is the handmaiden of the legal system. . . . If you claim to be science, you ought to put yourself to the test."
Although the panel's recommendations are not binding, they are expected to be influential. Among the recommendations:
* Create a new federal agency, the National Institute of Forensic Science, to fund scientific research and disseminate basic standards.
* Make crime labs independent of law enforcement. Most crime labs are run by police agencies, which can lead to bias, a growing body of research shows.
* Require that expert witnesses and forensic analysts be certified by the new agency, and that labs be accredited.
* Fund research into the scientific basis for claims routinely made in court, as well as studies of the accuracy and reliability of forensic techniques.
Those recommendations have been cautiously embraced by leading associations of forensic scientists, which in 2005 helped convince Congress that the study was necessary.
"You can't continue to do business in 2009 the way you did in 1915," said Joseph Polski of the International Assn. for Identification, whose members include examiners of fingerprints, documents, footwear and tire tracks. "We knew there would be things in there we'd like and things we didn't like."
Many forensic scientists were hesitant to criticize the report for fear of seeming resistant to testing and scrutiny. But there were some delicate complaints.
"It's not the science of forensic science that is in need of repair, I think; it's how the results are interpreted in the courtroom," said Dean Gialamis, head of the American Society of Crime Lab Directors, who was quick to add that his group welcomed the recommendations.