Bureau of Investigation, and the State Justice Institute. NCFDT should also have broad support from the American Society of Crime Laboratory Directors, the Genetics Society of America, and the American Society of Human Genetics.
The creation of an expert advisory committee is a somewhat unusual step for forensic science. However, we feel that it is the appropriate way to ensure that the field can incorporate new developments promptly while maintaining high standards.
Any new DNA typing method (or substantial variation on an existing method) must be rigorously characterized in both research and forensic settings, to determine the circumstances under which it will yield reliable results.
DNA analysis in forensic science should be governed by the highest standards of scientific rigor, including the following requirements:
Each DNA typing procedure must be completely described in a detailed, written laboratory protocol.
Each DNA typing procedure requires objective and quantitative rules for identifying the pattern of a sample.
Each DNA typing procedure requires a precise and objective matching rule for declaring whether two samples match.
Potential artifacts should be identified by empirical testing, and scientific controls should be designed to serve as internal checks to test for the occurrence of artifacts.
The limits of each DNA typing procedure should be understood, especially when the DNA sample is small, is a mixture of DNA from multiple sources, or is contaminated with interfering chemicals.
Empirical characterization of a DNA typing procedure must be published in appropriate scientific journals.
Before a new DNA typing procedure can be used, it must have not only a solid scientificcirclendation but also a solid base of experience.
Regarding RFLP-based typing, the committee makes a number of technical recommendations, including specific recommendations about the choice of probes, the use of ethidium bromide in gels, controls for anomalous bands, measurement of fragment sizes, controls for band shifting, match criteria, and sample retention.
Regarding PCR-based typing, the committee makes a number of technical recommendations, including recommendations for thorough characterization of each PCR assay for definition of the range of conditions under