The AAPP holds that the difference between truth and deception is as fundamental as the difference between right and wrong, and that the well-being and needs of communities, agencies, and individuals are best served by an objective and scientific approach to lie detection and credibility assessment. Polygraph testing, forensic psychophysiology, and credibility assessment, are evolving fields of science, intended to be used as decision support tools. These tools should aid investigators and referring agencies in making decisions about the truthfulness or deception of individuals in diagnostic and screening test circumstances. The role of scientific testing is to provide information, while professional evaluators are the final authority on all matters that require expert judgment. Decisions about truthfulness and deception are most effective when based on knowledge gained from empirical observation measurement and scientific decision methods. Valid and reliable decisions about truth and deception occur when all available information is utilized and evaluated in an objective, scientific and impartial manner, using the most current information, technology and techniques that are supported by scientific study.
The purpose of a psychophysiological detection of deception (PDD, polygraph) examination is to determine whether the examinee is being truthful or deceptive regarding an issue under investigation. PDD examinations may be conducted as screening exams, and may also be conducted as investigative or evidentiary examinations. This guide establishes recommended procedural elements for conducting a proper psychophysiological detection of deception (PDD) examination.
The polygraph examination should be a supplement to, not a substitute for, a field investigation.
The effectiveness of the polygraph examination, to a large extent, will be based upon the thoroughness of the investigation, prior to having the person take the examination.
To maximize the effectiveness of the polygraph examination, the investigator and the polygraph examiner should work together as a team.
Members conducting PDD examinations should meet the minimum initial training and continuing educational requirements, including attendance at one professional polygraph seminar on a yearly basis in order to maintain and improve their professional competency as defined in the AAPP Constitution.
To the extent possible, member examiners should be bound individually and collectively to the standards, objectives, and principals of practice of the American Association of Police Polygraphists, Inc., and existing law(s) in their respective jurisdictions. Members should avail themselves, as necessary and allowable, to periodic quality control review through the Association's Quality Control Committee or other quality control procedure.
Prior to any examination, member examiners should consult with investigators, review the circumstances, case facts and relevant documents in order to identify the PDD target issues.
Member examiners should ensure the instrument they intend to use is functioning in accordance with the manufacturer's specifications prior to beginning an examination.
Member examiners should strive to conduct all PDD examinations in settings that are sufficiently free from distractions that could interfere with the examinee's attention to the test stimuli.
The examiner should:
A minimum of two channels of respiratory activity shall be simultaneously recorded: one thoracic and one abdominal. A minimum of one channel of electrodermal activity, via resistance or conductance, shall be recorded. A minimum of one channel of relative blood pressure (cardiovascular) activity shall be recorded. Additional channels may be recorded but should not replace collection and recording of respiration, electrodermal and cardiovascular activity. Only data channels supported by published research shall be used for the formulation of an opinion.
The instrumentation and software shall permanently record the following: identity of examinee (as applicable), date and time of the examination, start/stop times of recording, pressure settings (when applicable), gain settings (when adjustable), any in-test instructions given examinee, stimulus onset, stimulus identification, end of stimulus, any answer given by examinee, standardized chart markings, and any changes made to the instrumentation or software during recording (such as pressure changes, centering adjustments and gain adjustments).
The polygraph examination should be recorded by audio or audio/visual means in its entirety, from the onset of the pretest interview through the completion of the posttest review, unless prohibited by law, rule or regulation. The recording should be continuous, and any stops or pauses should be explained on the recording. All PDD examination records and recordings shall be retained and maintained for a minimum of one year or longer as may be required by law. Questions should be presented in such a manner as to not influence the examinee's responses.
Member examiners should make and maintain a continuous recording of the data produced during the in-test phase.
Question intervals for deception tests shall allow for a reasonable recovery and stimulus onset to stimulus onset should not be less than 20 seconds, though a minimum of 25 seconds is recommended.
The member examiner should evaluate the test data using a numerical evaluation method for which there are known error and accuracy rates reported in published and replicated research.
Examiners should maintain all records of test data analysis in accordance with ASTM standards or their agency policy.
Examiners should collect a sufficient amount of physiological data suitable for evaluation in compliance with the format utilized.
All suitable physiological data shall be evaluated and considered when formulating an opinion.
Following collection of all physiological data, a discussion of the examination shall be conducted, as appropriate.