practice or poor sample handling and labeling; and, because DNA typing is technical, a jury requires the assurance of laboratory competence in test results.
At issue, then, is how to achieve standardization of DNA typing laboratories in such a manner as to assure the courts and the public that results of DNA typing by a given laboratory are reliable, reproducible, and accurate.
Quality assurance can best be described as a documented system of activities or processes for the effective monitoring and verification of the quality of a work product (in this case, laboratory results). A comprehensive quality-assurance program must include elements that address education, training, and certification of personnel; specification and calibration of equipment and reagents; documentation and validation of analytical methods; use of appropriate standards and controls; sample handling procedures; proficiency testing; data interpretation and reporting; internal and external audits of all the above; and corrective actions to address deficiencies and weight their importance for laboratory competence.
Although standardization of forensic practice is difficult because of the nature of the samples, DNA typing is such a powerful and complex technology that some degree of standardization is necessary to ensure high standards.
Each forensic-science laboratory engaged in DNA typing must have a formal, detailed quality-assurance and quality-control program to monitor work, on both an individual and a laboratory-wide basis.
The Technical Working Group on DNA Analysis and Methods (TWGDAM) guidelines for a quality-assurance program for DNA RFLP analysis are an excellent starting point for a quality-assurance program, which should be supplemented by the additional technical recommendations of this committee.
The TWGDAM group should continue to function, playing a role complementary to that of the National Committee on Forensic DNA Typing (NCFDT). To increase its effectiveness, TWGDAM should include additional technical experts from outside the forensic community who are not closely tied to any forensic laboratory.
Quality-assurance programs in individual laboratories alone are insufficient to ensure high standards. External mechanisms are needed, to ensure adherence to the practices of quality assurance. Potential mechanisms include individual certification, laboratory accreditation, and state or federal regulation.
One of the best guarantees of high quality is the presence of an active