Judge Michael McC _ nick - Voice For The Defense Online

Polygraph Usage for Attorneys in Criminal Casesby Bill ParkerPolygraph examinations are used ex- 4. Examination procedures and when the client insists on taking an extensivelyby attorneys and law enforce- 5. Validity of polygraph amination.ment officers across the United States.They shouldbeused as investigative toolsand are of value in certain situations;I. Basic polygraph function 3. Selection of apolygraph examinerhowever, they do havetheirlimitations and Thebasicfunctionofapolygraphis that In choosing a polygraph examiner, it isshould not be viewed as a panacea. It be- of a recording device. It records certain recommended that the first considerationhooves any attoniey practicing criminal physiological responses to psychological be his reputation. The examiner shouldlawtoday tohavea workingknowledgeof stimuli, the stimuli being the examination haveanestahlishedreputationforintegritypolygraph procedures and practices. questions. Fear of deception causes major and fairness, as well as forhis technical ex-The theory of the technical aspects of and immediate physiological changes in pertise. He should have a background inpolygraph procedures includes knowledge the human body. These changes take dealing with forensic issues and should beof the psychological and physiological meaning from empirical data produced by familiar with the personality types whichsciences, but these will not be thoroughly scientific research. are commonly involved in these types ofdiscussed in this article. This article will It is critical to understand and beaware cases. The examiner should be trained inprovide attorneys with a working know- of the fact that there are some examiners the use of a numerically scored zone comledgeof polygraph examination proce- practicing today whose evaluation of data parison technique. The facility employeddures and their use in criminal cases and produced during polygraph examinations by the examiner should have a videowill answer the most common questions is not based on scientific research. An ex- monitoring and recording capability.asked by attorneys.aminer may use one of several modemAlist ofreading material is provided for methods of evaluation, but they all share 4. Examlnafionproceduresthose who wish to go into more detail on one key term - zone conparison. Onlythe subject of polygraph. the zone comparison technique has been Examinations consist of two majorThere are several basic issues relating shown to result in an objective, numerical- phases. The fast phaseis calledthepre-testto polygraph examinations with which at- ly scored evaluation of the data produced inte~iew.Dnring this phase, theexaminertomeys should be familiar. during the examination. atkmpts to establish rapport with the snb-1. Basic polygraph function ject and convincehim that theexamination2. Common polygraph uses by attor- 2 Commonpolygraph uses byatlorneys will he conducted in aprofessional, objecneystive, and impartial manner. After some3. Selection of a polygraph examiner The situations where a polygraph ex- background information has been obaminationwill be useful are best deter- tained, the subject is allowed to give a perminedby an attorney in a given case, and sonal account of his involvement in theill parker born June jO, 1943 ill thus its usefulness is limited primarily by case. The polygraph technique and all ex-Dallas, Texas. the attorney's insight, knowledge of ply- amination questions are then reviewedH~ obtairleda B ,~, Degree in Crimbml pph, and ability to evaluate each par- with the subject so that he will know ex-Justicefrom Sa,n Houston Srate College in t~cular case. As a general rule, the test actly what questions will be asked on theHuntsville, Texas. questions should avoid anyhng that calls test. The review of the questions alsoill becallle a liceILEed polygraph ex- for a conclusion, opinion, or deduction, provides an opportunity to clarify any amatnine,.ill T~~~~ ilt 1980, He a mneln- suchas,"Didyou intendtok ill... ,"etc.,and biguities with regard to the relevant quesberofrhe~allas,TeuzsPo,iceDepnnlllent should be restricted to factual events that tions. The review of the polygraphfront 1964-1984. H~ retire. as eitherdid or didnot occur, such as, "When technique includes a brief explanation ofhaving spent n,ost of his in the JohnDoewasshotonMarch 15,1988,was how the autonomic nervous systemfunc-Criminal Investigation Division. He has the gun that shot him in your hand?" tions, causing phys-iological reactionsbeell president ofParker. Jor,es, Inc. since Some of the more common reasons at- which are recorded by the polygraph.1984, parker- J ~ is a ~ polygraph , ~ fin,, torneys contact ow office to request a The test subject is then attached to the~doillgan extensive anlorrrlt oflegal work in polygraph examination are: to verify the polygraphinshument, whichcontinuouslythe north Texas area. . statements of their clients for their own and simultaneously records electrcdermalH~ has been a speaker for the Dallas satisfaction; to approach the government's resistance, respiration, and cardiovascularB~~ ~ ~ D~~~~ c ~ ~ ~ i ~ attorney; , ~ ~ as ~ a ~ preliminary ~ ~ i fact-finder; ~ ~ activity ~ while i the test questions ~ are ~ ,A~~~~~~~~ zs Ofice, Texas District and when theclient is acontrol problem; to sort reviewed and answered. After all the ques-~ounry~,torlleys~Associationsall~ot~,er out responsibility for a particular client tlons have been answered and thesimilar organizations. whenmore thanonedefendant isinvolved, physiological responses recorded, thesub-30 VOlCEfor fhe Defense I January 1989