Tuesday, March 3, 2009

NAS report on the state of forensic science

Last month the National Academy of Sciences released the pre-publication copy of its report on the state of forensic science in the United States, Strengthening Forensic Science in the United States: A Path Forward. Congress authorized the report as part of the Science, State, Justice, Commerce and Related Agencies Appropriations Act of 2006.

The report notes that advances in some of the forensic sciences, notably DNA analysis, have shown the potential to assist law enforcement in identifying criminals and in resolving unsolved cases. But the report also notes that reliance on faulty science or techniques has led to the convictions of innocent citizens.

"...in some cases, substantive information and testimony based on faulty forensic science analyses may have contributed to wrongful convictions of innocent people. This fact has demonstrated the potential danger of giving undue weight to evidence and testimony derived from imperfect testing and analysis. Moreover, imprecise or exaggerated expert testimony has sometimes contributed to the admission of erroneous or misleading evidence."

The Academy expressed concern about the fragmentation of the forensic sciences. Most of the forensic analysis is conducted by state and local jurisdictions which are subject to budget reductions in times of economic distress. Problems also arise because there is no national coordination in many of the forensic sciences, leading to lack of standardization and accreditation in the nation's crime labs.

This fragmentation and lack of standardization means that the term forensic science is a bit, shall we say, fuzzy. There is no consensus across the sciences as to technique, methodology, reliability, rate of error or general acceptability. Some of the forensic sciences are laboratory-based, such as DNA and drug analysis, while others are expert "interpretations" of observed data, such as bite mark and fingerprint analysis.

"With the exception of nuclear DNA analysis, however, no forensic method has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source."

The difference between laboratory-based and expert "interpretation" forensic sciences should, according to the Academy, play a role in the admissibility of forensic evidence in criminal trials. Courts should look to the extent to which the forensic discipline is founded on a reliable scientific methodology as opposed to interpretation (that could be tainted by error, bias or lack of standards). The Academy criticized the nation's courts for abandoning their role as gatekeepers of scientific and expert testimony laid out in the Supreme Court's decision in Daubert v. Merrell Dow Pharmaceuticals (Kelly v. State is the seminal case in Texas).

The report notes that in reported appellate decisions, expert testimony offered by the prosecution is rarely excluded and appeals are routinely denied for defendants contesting the admission of expert testimony by the state.

The Academy calls for more certification and standardization in the forensic sciences and for "crime labs" to be separated from state and local law enforcement agencies. The report calls for the creation of a national body to oversee the forensic sciences.

"The entity that is established to govern the forensic science community cannot be principally beholden to law enforcement. The potentional for conflicts of interest between the needs of law enforcement and the broader needs of forensic science are too great."

Too often, defense experts are painted with the brush of being hired guns while expert witnesses for the state are portrayed as scientists. Jurors don't seem to understand that most of the state's experts work in and for law enforcement. Some of that fault lies with the criminal defense bar and some of it lies in the jurors' misunderstanding of the way in which the forensic sciences operate in the criminal justice system.

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