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Polygraph (lie detector)

It is hard to conceal excitement: it is revealed by changes of physiological reactions of a person (pulse rate becomes more or less rapid; rhythm of breathing, static skin conductivity, blood pressure, body temperature, character of brain action currents, intensity of  salivation, motion activity of hands change), and it is quite difficult to learn to control them.
Qualified specialists of our company having abundant work experience use the most modern equipment and up-to-date software in their work. 
Objectives of use of a polygraph
Holding an interrogation with the use of a polygraph or other technical device which allows to estimate trustworthiness of given information, may be useful in certain cases, for example, when a new employee is employed, especially if the matter is about one of key positions in a company. The use of a polygraph in the course of an interview will help the employer to get answers to the following important questions:
·        if an applicant is connected with competing firms or criminal environment;
·        if he wants to conceal some facts of his biography (for example, commitment of penal acts in the past);
·        if he has undesirable inclinations (alcoholism, drug usageetc.);
·        if an applicant has negative personal features.
The interrogation of working personnel with the use of a polygraph, apart from getting answers to above-listed questions, enables a chief:
·        to estimate degree of loyalty of employees;
·        to revealfacts of violations of prescribed norms of activity of enterprise (theft, transfer of secret information to competitors etc.).
Holding an interrogation
The interrogation with the use of a polygraph is based on the hypothesis which assumes that presentation to a subject of certain questions-stimuli connected with important events of his life, is able to provoke him into corresponding feelings of fault, alarm, anxiety. That is why before a check, it is important to create an atmosphere in which a person would have again anxieties experienced by him during accomplishment of one or another action.
Creation of conditions for holding an interrogation with the use of a polygraph 
On taking the decision about the use of method of interrogation with the use of a polygraph, you must warn an applicant about the coming test not later than one day before. Also it is necessary to explain to the person his rights and essence of the coming procedure. Questions are presented to the checked person beforehand. Questions which perplexed him are discussed in detail. The employer must get a voluntary consent of the checked person confirmed in written form to passing of the polygraph.
Methods of interrogation with the use of a polygraph and procedure of holding a test  
The preliminary interview is considered an obligatory component during the procedure of check with the help of a polygraph and includes partly an orientation which is carried out by a psychologist in any experiments directed to detection of overall indexes. When instructing, the operator emphasizes purposely categorical answers, that is «yes» or «no», and warns that the device will register any inaccuracy or insincerity. During a conversation, the polygraphologist also tries to find out circumstances and factors which will be checked by readings of physiological functions. Let us suppose, if the checked person took medical preparations, how he slept, if he has any illnesses. The polygraphologist pays big attention to clarification of separate facts of biography of the checked person. At the preliminary interview, they discuss topics connected with the coming test, for example, details of biography, peculiarities of relations with colleagues at previous place of work, if the matter is about the check of a person who is employed. Questions which will be significant for this person are formulated and selected on the grounds of results.
The next stage — a stimulating test — is usually carried out directly after the preliminary interview. It is reduced to identification of a certain card with a numeral or a word which the checked person chooses from the common pack. Thus, the polygraphologist demonstrates visually the ability of the polygraph to indicate a chosen card. The stimulating test has the purpose to persuade the checked person of accuracy of readings of the device, to differentiate more his reactions to different questions during the test.
The stimulating test is followed by the main procedure. The choice of a necessary method depends completely on a task for which the check is carried out. If a concrete incident or a crime is checked, one series of questions is needed. If it is necessary to check reliability of an applicant, different questions are asked respectively among which three groups are distinguished:
·        critical questions connected directly with the subject of the check. For example, with one of aspects of a happened theft in the institution;
·        neutral questions which, unlike critical ones, are not connected with the carried out investigation and exert insignificant influence on the checked person. They must not create a heightened emotional reaction. Neutral questions are necessary in order to create a background for comparison of reaction of the checked person to critical questions and to neutral ones. A significant difference will mean a manifestation of lie;
·        control questions which are not connected, like neutral ones, with the subject of investigation, but they, unlike the latter ones, still carry a significant emotional load. One can ask the checked person: «Have you ever been late for a serious event?» This question is control because everybody during his life was late formerly for important events. And if, for example, the purpose of the check is employment, the person, perhaps, will not want to confess his beings late. That is why he may get perplexed. However, the perplexity still will be smaller than the perplexity provoked by the answer to a critical question.
There are three methods of making up a questionnaire. The choice of a concrete method depends on a task set for the polygraphologist. So, the method of alternation of critical and neutral questions is often used during the check of an applicant for a vacant position in the company. Answers of the checked person are written down on paper and recorded on tape, then operators compare how the person reacted to the group of neutral and critical questions and estimate whether there is a distinction or not.
The second methodology of asking questions — including five control questions — is the most widespread method of control during carrying out an investigation of concrete affairs. Such a questionnaire contains questions which are formulated in order to make the checked person change his physiological readings. The idea is to measure the general activity of the individual and compare it with the reaction to critical questions.
The third methodology of asking questions is a test with hidden questions. It is used with the purpose to find out the information about a crime which is known only to persons who committed it. In this case, when forming a questionnaire, the polygraphologist must know concrete details which only a guilty person could see. For example, the stolen money was in an envelope of yellow colour. Then a hidden question will be as follows: «Did you hold in your hands an envelope of YELLOW colour yesterday?». The visual memory of the interrogated person will stimulate at once his physiological reactions to this question.
Trustworthiness of results 
Though the method of interrogation with the use of a polygraph is one of the most accurate ways of getting information about trustworthiness of data informed by a person, the polygraphologist can hardly give hundred-per-cent guarantee of correctness of results. The efficiency of the check with the help of a polygraph varies by majority of estimates in the range from 70 to 90%, and sometimes even higher. That is why the data obtained during the holding an interrogation with the use of a polygraph, have probabilistic character. Perhaps, when taking a decision, one may not rely only upon the information obtained as a result of holding an interrogation with the use of a polygraph.