The Use of Polygraph Tests by Law Enforcement Essay
The Use of Polygraph Tests by Law Enforcement
How Reliable are Lie Detectors?
Lie detectors are not completely reliable.
White Jr., R. D. (2001). Ask me no questions, tell me no lies: examining the uses and misuses of the polygraph. Public Personnel Management, 30(4), 483+.
This article discusses the different ways by which the polygraph is used and misused, and recommends certain guidelines for the proper use of polygraphs. It presents both sides of what appears to be a long standing debate on the reliability of lie-detector tests, integrating significant legal developments in the discussion. This is a good article because it outlines the history of polygraph development and use, and contrasts the pros and the cons of using polygraphs in the public sector and in law enforcement. The article, however, may be considered a bit flawed in the sense that it seems to imply that there is nothing wrong with using polygraphs.
In this connection, it must be pointed out that the author only prescribes the use of the polygraph in narrowly-tailored, tightly circumscribed instances, which, upon a deeper analysis, means that the author is against the wholesale, indiscriminate use of polygraphs. In other words, the author seems to imply that as a general proposition, the use of polygraphs or the results taken therefrom are not completely reliable, and may only be considered as such in certain instances. Another strength of the article is that it discusses not only the technical aspects of polygraph use, i.e., its validity and reliability, but also its legal and ethical or moral implications.
The article is relevant to the above topic because it discusses the use of polygraphs not only against criminals, but as against the individuals that compose the public sector. It lays down the premise that despite the controversy regarding the use of polygraphs in the past, at present, its use has become more widespread and is applied not only to criminals or suspected criminals, but also to government employees and in government agencies, who are on the right side of the law.
With respect to the article’s relevance to the question on the reliability of lie detectors and the statement that lie detectors are not completely reliable, as mentioned, the article presents both sides of the argument, and the conclusion implies that, in fact, lie detectors are not completely reliable because if they were, they could be used at any given instance, at any given time, without having to prescribe specific parameters for its use.
The main argument for the continued use of polygraphs is that in numerous cases, the physiological responses elicited by questioning indicate the guilt or innocence of a person, because of the way people are supposed to react when they are lying or telling the truth. The easiest criticism against the reliability of characterizing outcomes such as increase in pulse is that each person reacts differently to a particular situation.
Hence, the person may be telling the truth, but he may feel nervous at being questioned and being strapped to a machine, so his pulse may be uneven. Studies conducted, particularly by the Office of Technology Assessment or OTA, show that there is a large variance in the cases where the individual who was tested via polygraph was held to have been telling the truth when he was actually lying, or when he was found to be lying when he was actually telling the truth.
Also assailed is the lack of training of the people who operate polygraphs, and the lack of operational guidelines in the actual use of the machines, as well as the use of what are called countermeasures that enable certain individuals to “beat” the polygraph. In conclusion, the author concedes that reliable or not, polygraphs will still be used, and thus proposes several tests or criteria by which to determine whether or not a polygraph should be used, such as the existence of a compelling public interest, the presence of independently corroborating evidence, and the imposition of stricter controls with respect to actual testing. The use of such criteria could mitigate the inherent unreliability of polygraph testing.
Dripps, D. A. (1996). Police, plus perjury, equals polygraphy. Journal of Criminal Law and Criminology, 86(3), 693 to 716.
The article presents the author’s theory that making polygraph examination results admissible in evidence as a general proposition will ward off the evil of perjury committed by law enforcement agents. The arguments presented by the proponent are very structured and organized. The author paints a very convincing picture of the disadvantages and prejudice brought about by the current general rule on the inadmissibility of polygraph test results vis-à-vis police testimony with respect to suppression hearings.
The only weakness of the article is that it concedes, even if merely for the sake of argument, that polygraph testing results are generally unreliable, but they should be used anyway to at least ensure that policemen do not commit perjury on the stand when they testify as to the factual milieu of the case and the seizure of evidence. It is a good article to contrast with the first because the arguments are similar but the conclusions and implications are different, and the details should be examined more closely to determine why, despite the similarities, there still exists a discrepancy or difference in opinion.
The article is relevant to the above-mentioned topic, because it relates to the use of polygraph tests by and against law enforcement officers. Like the first article, it presents the use of polygraphs not only as against suspected criminals, but even against those on the other side of the law. It is relevant to the question on the reliability of polygraph testing and on the thesis that polygraph tests are not completely reliable because it argues against the thesis by citing the rules on evidence.
In the case of Daubert v. Merrell Dow Pharmaceuticals, the Supreme Court held that the use of expert testimony based on valid science is admissible in evidence. Despite the controversy as to its reliability, several scientific agencies have attested to the valuable use of polygraphs and have provided for acceptable margins of error; after all, nothing is perfect, and to expect that polygraph results are a hundred percent reliable would be an exercise in futility. With the allowable margin of error, polygraph results are made more reliable.
The article points out the background behind the OTA study; it was undertaken at the behest of the legislature on a move to be more stringent in regulating the use of polygraphs. Many government institutions and agencies rely on polygraphs to help them ferret out the truth, such as the CIA, the FBI, and the Department of Defense.
The article stresses that in general, polygraph test results can be relied upon, because it involves a science that has been empirically and objectively tested, and when the testing is done properly, the margin for error is acceptably low.
In the specific context of suppression hearings, the admissibility of polygraph results as explained through expert testimony would better protect the rights of the accused, as many policemen are unfortunately wont to lie even under oath to ensure that crucial evidence does not get thrown out and the case against the accused does not fall apart. At the very least, the admission of polygraph results would make law enforcement officers, and criminals, think twice about lying on or off the stand, and would contribute in some way to the proper administration of justice.