groups and the highest of these values or 10% (whichever is the larger) should be used. Data on at least three major "races" (e.g., Caucasians, blacks. Hispanics, Asians, and Native Americans) should be analyzed.

  • Any population databank used to support DNA typing should be openly available for scientific inspection by parties to a legal case and by the scientific community.

  • Laboratory error rates should be measured with appropriate proficiency tests and should play a role in the interpretation of results of forensic DNA typing.


Critics and supporters of the forensic uses of DNA typing agree that there is a lack of standardization of practices and a lack of uniformly accepted methods for quality assurance. The deficiencies are due largely to the rapid emergence of DNA typing and its introduction in the United States through the private sector.

As the technology developed in the United States, private laboratories using widely differing methods (single-locus RFLP, multilocus RFLP, and PCR) began to offer their services to law-enforcement agencies. During the same period, the FBI was developing its own RFLP method, with a different restriction enzyme and different single-locus probes. The FBI's method has become the one most widely used in public forensic-science laboratories. Each method has its own advantages and disadvantages, databanks, molecular-weight markers, match criteria, and reporting methods.

Regardless of the causes, practices in DNA typing vary, and so do the educational backgrounds, training, and experience of the scientists and technicians who perform the tests, the internal and external proficiency testing conducted, the interpretation of results, and approaches to quality assurance.

It is not uncommon for an emerging technology to go without regulation until its importance and applicability are established. Indeed, the development of DNA typing technology has occurred without regulation of laboratories and their practices, public or private. The committee recognizes that standardization of practices in forensic laboratories in general is more problematic than in other laboratory settings; stated succinctly, forensic scientists have little or no control over the nature, condition, form, or amount of sample with which they must work. But it is now clear that DNA typing methods are a most powerful adjunct to forensic science for personal identification and have immense benefit to the public—so powerful, so complex, and so important that some degree of standardization of laboratory procedures is necessary to assure the courts of high-quality results. DNA typing is capable, in principle, of an extremely low inherent rate of false results, so the risk of error will come from poor laboratory

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