Some Thoughts on Quality Concerns in Crime Laboratories

Article Posted: June 01, 2009

According to the much anticipated crime laboratory study report released by the National Academy of Science (NAS) on February 18, 2009, a “badly fragmented” forensic science system needs an overhaul. The report raises questions as to the scientific validity of fingerprint identification, firearms identification, and bite mark identification in particular, pointing to the exhaustive baseline testing and the stringent training requirements and examination protocol associated with nuclear DNA testing.

The report states that it is beyond the scope of the courts to be able to effectively regulate the scientific reliability of scientific testimony. Recommendations include mandatory accreditation of crime labs and certification of individual examiners. Removing crime labs from law enforcement agency control so as to reduce confirmation bias is proposed. Overall control of crime lab policies and procedures should be standardized through the creation of a National Institute of Forensic Science, according to the report.

Some of the Issues
One of the determining factors relating to the admissibility of scientific testimony in court proceedings, according to the Daubert decision (Daubert v. Merrill Dow Pharmaceuticals, 509, U.S. 579, 1993), is the error rate associated with a particular procedure. This has proven to be elusive within many disciplines for a number of reasons. First and foremost, it is virtually impossible to know when a finding is in error and when it is not since it is only very rarely possible to independently establish the true source of evidence (i.e. fired bullets, fingerprints, footwear impressions, etc.).

The latent fingerprint community has long subscribed to a zero rate of error for fingerprint identification. The basis for this declaration has simply been that no two fingerprints from different sources have been identical. This line of reasoning has been challenged both in the literature and in court. As pointed out in the NAS report, adequate research is lacking in this area.

With the advent of formal proficiency testing programs, such as that offered by Collaborative Testing Services beginning in 1971, some laboratories have attempted to relate error rate to proficiency test results. Given the fact that examiners know when they are being tested, it is pretty naïve to presume that the results of such testing are in any way representative of actual error rate. At best, such rates might be categorized as the minimum error rate, especially given the potential for test compromise. Clearly, blind tests are needed.

The obvious problem with constructing totally blind tests in general is the associated paper trail that is required. That becomes more difficult to pull off in smaller labs, especially those in which there is typically interaction between the analyst and the case officer. Basically, a conspiracy of sorts would be required, due to the typical number of involved individuals in a real case, for blind testing to work in those situations.

Laboratory accreditation is mostly voluntary and is available through the American Society of Crime Laboratory Directors Laboratory Accreditation Board (ASCLD-LAB). Accreditation is granted to the organization, not the individual analysts. Texas, Oklahoma, and New York have required accreditation. When a forensic scientist leaves an accredited lab and goes to work in an unaccredited lab (approximately 80% of the crime labs in this country are accredited by ASCLD-LAB according to the NAS report of 02/18/09), the accreditation does not go with them. This serves as the impetus for certification of individual forensic scientists in addition to accrediting the organization to which they belong. Certification, like accreditation, is not currently required by most crime labs in the country.

Certification is available through a variety of specialty certification programs such as the American Board of Criminalistics (ABC). These specialty certifications are overseen by their voluntary membership in the Forensic Specialties Accreditation Board (FSAB) created by the American Academy of Forensic Sciences (AAFS).

Related Topics: Legislation/Rulings Reference Materials Training Point of View June/July 2009