The research aimed to determine the feasibility of preparing and distributing different classes of physical evidence, assess the accuracy of criminalistics laboratories in processing selected samples, conduct statistical studies of the tests administered, and establish the basis for designing training programs to improve proficiency. The results revealed that voluntary, anonymous proficiency testing is both feasible and necessary as indicated by the consistently high participation rates of laboratories throughout the research. In addition, ongoing proficiency testing is needed to monitor efforts to improve and maintain high quality criminalistics services. Moreover, laboratories vary widely in their proficiency. Furthermore, the majority of laboratories lack the money to take part in proficiency testing on a subscription basis. Recommended actions include establishing a nationwide program of continuous proficiency testing, technical assistance to laboratories requesting it, training, and adequate funding. Tables, forms, footnotes, list of participating laboratories, map, and 30 references