Question

Do you think the use of polygraph in the hiring processes for police agencies is an important tool, along with others is effective enough to identify and eliminate unsuitable candidates for employment? please provide a source  

Answer 1

A Polygraph or lie detector is a diagnostic instrument that records physiological changes in a person caused by stress. It relies upon measuring the body's involuntary responses which occur when the subject is being deceptive or untruthful.

The purpose of the employment polygraph test is basically to determine whether a candidate has been truthful on their job application. Any indication of deception can be cause for disqualification from consideration for employment. Answers from the pre-exam questionnaire might also indicate background disqualifiers, especially if they show previously undetected serious crimes or if the answers are different from those given on the supplemental application. The application of polygraph in a public safety preemployment screening is complex from the outset, and is best understood by starting with brief review of the putative psycho-physiological concepts that underlie polygraph techniques, procedures, and test interpretation. These issues should be understood in the more general context of the inherent complications that are common to all screening tests. Because it is unrealistic to expect perfection from any test, whether medical, psychological, or investigative, informed consumers of polygraph test results should become familiar with common testing concepts including; sensitivity, specificity, hit-rates, miss-rates, false-positives, false-negatives, and base-rate influences along with the ways that these may affect polygraph screening outcomes.

Source-

Handler, M., Honts, C.R., Krapohl, D.J. et al. Integration of Pre-Employment Polygraph Screening into the Police Selection Process. J Police Crim Psych 24, 69–86 (2009). https://doi.org/10.1007/s11896-009-9050-2