As an investigator you have a wide variety of tools at your disposal. Regardless of what type of investigation you are conducting, seeking the truth. Truth can be an elusive commodity in many instances. Victims, witnesses, and sometimes clients, are less than forthcoming in the information they provide to an investigator. As a matter of fact there are a number of different types of liars out there in your world. Here are just a few:

The Panic Liar-This guy or girl will only tell you the truth if and when they are convinced that they are in deep trouble.

The Occupational Liar-This individual will tell you the truth only if he believes it will better his position.(Many automotive and other salespersons are highly skilled in this regard)

The Conditioned Liar-He or she has been conditioned to lie from a young age.

The Sadistic Liar-he knows that you know the truth. However, he generally won;t confess. he enjoys the "lime-light" and attention being generated by your investigation.

The Neurotic Liar-This individual lies even to himself. He is too weak to admit what he has done.

Recognizing the type of liar you are dealing with, often provides a useful key in developing a sound interview and/or interrogation strategy. That however might be a topic for another article. Regardless of the type of liar you may encounter or the type of investigation you are conducting, forensic psychophysiology is often a most effective way to determine the truth. Weather trying to verify an alibi, a victim's account of events, or your client's version of things, a forensic psychophysiologist in the detection of deception(PPDD for short), can often provide valuable information. Some people get really excited being able to write lots of letters after their name. The world is full of B.S.,Ph.D.,M.S., and now PPDD, types. I generally like to refer to myself and other PPDD types as polygraph examiners or polygraphists.

If properly conducted by a certified and well trained expert specific issue polygraph testing has demonstrated an accuracy rate of 93%-95%. Many examiners have additional advanced training in interview/interrogation techniques, nerurolinguistics, and related disciplines. Don't be afraid to ask your examiner about his or her specialized training.

Today's polygraph is computerized unit. The days of mechanical instruments with moving pens, messy ink, and chart paper are slowly moving behind us. A lot of $75.00 shirts and other more personal items (sometimes body parts) have been permanently damaged by ink spills over the years. The computerized polygraph uses digital technology,.Some experts claim that the computerized units are more sensitive to small physiological changes than their mechanical counterparts. I think the jury is still out on that question. Polygraph instruments measure upper torso movement, heart rate/blood pressure changes, and galvanic skin response(seating). Why do these involuntary changes take place when a person lies? Most people are conditioned at a young age not to tell lies. As children grow older, life experience in most instances, reinforces all of the positive values taught at a young age. Each time a person does something they were taught not to do, including lying, some changes take place inside their bodies. These changes are initiated by their brain (hence the physiologic designation). Approximately 10% of the population are not good subjects for polygraph testing. Some people refer to these folks as path0ological liars. They make up only one segment of that 10%. The other members of that group are often persons who have had serious mental health issues over the course of their lives. To put it simply, their mind and bodies don't react in a manner required for a polygraph examiner to obtain useful charts during the exam process.

The average polygraph exam if properly conducted takes about two hours to complete. Much of that time is spent in a pre-test interview. The pre-test interview is important. During the typical pretest interview, the examiner reviews the instrumentation with the subject, properly adjusts the instrument to the subject, and reviews the specific issue and exam questions with the subject. The actual polygraph testing generally consists of three short test about five minutes each in length.

Attorneys and Investigators conducting criminal defense investigations use the polygraph often as part of a defense strategy. In some instances, prosecuting attorneys are open to having the defendant take a polygraph exam. This happens more often when the State does not have a real strong case. Word to the wise, never let your defendant/client take a State sponsored law enforcement polygraph exam until he or she has completed an exam with a private examiner. it's nice to know how your client will do on the test before you give law enforcement a shot at polygraph ore even worse, interrogation after the polygraph. Investigators often use polygraphs to verify alibi defenses and witness accounts. Multiple suspects can be eliminated from suspicion using the polygraph. On the civil side, many individuals submit to polygraph testing in order to prove fidelity in their marriages or relationships. In Connecticut, private investigators hired by employers, generally cannot use the polygraph in work place investigations. Connecticut State Statue 31-51g will provide you with information on the appropriate use of polygraph in the work place. When seeking the truth, forensic psychophysiology can move you in the right direction.

(Alfred J DelCiampo is Chief Polygraphist at A.D.M.Associates, Bloomfield, CT 06002)

BACK