The Employee Polygraph Protection Act of 1988 (EPPA) prohibits most private employers from using polygraph testing to screen applicants for employment. It does not affect public employers such as police agencies or other governmental institutions. In the testimony regarding EPPA it became clear that there were no current and reliable data on a variety of important issues about police applicant screening, although polygraph testing had reportedly been used for that purpose since at least the early 1950's. In recognition of this gap, the APA Research Center at Michigan State University embarked on a survey of police executives in the U.S. to determine the extent of, and conditions in which, polygraph testing is being used for pre-employment screening The survey population included 699 of the largest police agencies in the United States, excluding federal agencies, and produced usable returns from 626 agencies, a response rate of 90%. The major results of the survey showed the following:

Among the respondents, 62% had an active polygraph screening program, 31% did not and 7% had discontinued polygraph screening, usually because of prohibitive legislation. These results make it clear that a great majority of our largest police agencies do have a polygraph screening program in effect. These agencies employ, on average, 447 officers and service a population averaging 522,000 citizens. They primarily use the polygraph to screen applicants for sworn positions, although 54% also screen persons interested in non-sworn positions. Approximately 25% of the persons tested are disqualified from police employment based on the information developed during polygraph testing which, by the way, is used both to verify information provided in an application form and to develop information that cannot be gotten by other means. Only a very small proportion (2%) of agencies use polygraph testing as a substitute for a background investigation. A rank ordered listing of topics covered during polygraph testing revealed that investigation of illegal drug usage, employment related dishonesty, and involvement in felonies are the most important.

When asked to indicate what their reasons were for using polygraph screening, the great majority of the agencies indicated that it reveals information that cannot be obtained by other selection methods. Closely following this item in order, was that polygraph testing makes it easier to establish background information, that it deters undesirable applicants, and that it is faster than other methods of selection. The three leading benefits of polygraph screening were that applications were more honestly completed; that higher quality employees were hired; and that there were fewer undesirable employees. Over 90% of these agencies expressed either moderate or high confidence in their polygraph screening program and 80% of them reported that in their experience the accuracy of the testing ranged between 86%-100%. The only procedure that was considered to be as useful as polygraph screening was a background investigation; all others, including written psychological tests, psychological or psychiatric interviews, personal interviews, and interviews by a selection board were judged to be less useful. Finally, this survey also showed that polygraph screening revealed applicant's involvement in serious, undetected criminality. For example, 9% of the agencies said that polygraph screening detected involvement by some applicants in unsolved homicides; 34% indicated some applicant involvement in forcible rape; and 38% showed some applicant participation in armed robberies. Other serious, unsolved crimes, such as burglary, arson and drug offenses were also revealed by polygraph screening.