Polygraph Test (Lie Detector Test)

A Scientific Forensic Method for Truth Verification

A Polygraph Test, commonly known as a Lie Detector Test, is a professional forensic assessment method used to assist in truth verification through physiological and psychological analysis.
BIFPS Consultancy Ltd. (ForensicBD™) was the first organisation to professionally introduce this service in Bangladesh.

As the first specialised polygraph examination institution in Bangladesh, we provide truth-verification assistance using internationally recognised forensic methodologies, psychological assessment, behavioural analysis, and modern computerised polygraph systems.

What is a Polygraph Test?

A polygraph test is a scientific assessment process in which involuntary physiological responses are measured and analysed while a person answers specific questions.
The examination is conducted by trained forensic professionals and certified polygraph examiners.

The primary objective of the examination is to identify physical and psychological response patterns that may indicate stress, deception, concealment of information, or truthfulness.

How Does a Polygraph Test Work?

During the examination, a computerised polygraph instrument simultaneously records multiple physiological changes, including:

• Heart Rate
• Blood Pressure
• Respiration Pattern
• Skin Conductance / Electrodermal Activity
• Movement Detection
• Pupillary & Behavioral Responses

When a person experiences deception or psychological stress, the autonomic nervous system may produce involuntary physiological reactions.
These responses are analyzed by trained polygraph examiners through standardized scoring systems, computerized chart analysis, and behavioral assessment techniques.

Our Modern Polygraph System

We use advanced computerised polygraph examination systems, including:

• CPS Elite System with Electronic Pneumos
• CPS Plethysmograph
• CPS Elite Complete Movement Sensor Package, including:
• Masseter Headset
• Arm Sensors
• Feet Sensors
• Seat Sensor

These advanced technologies help monitor physiological responses more accurately and reduce movement-based countermeasures during examinations.

Stages of Our Polygraph Examination Process

1. Case Assessment & Pre-Test Interview

Before the examination, the examinee undergoes a detailed interview process where case-related information, behavioural indicators, and psychological background are assessed.

This stage may include:

• Psychological Profiling
• Behavioural Observation
• Body Language Analysis
• Question Structuring & Validation

The examinee is informed in detail about the examination procedures, limitations, and consent-related matters.

2. Polygraph Examination Phase

Scientifically structured questions are prepared according to the context of the case.
During questioning, the computerised polygraph system simultaneously records physiological responses.

3. Data Analysis & Interpretation

Collected physiological data are analysed through:

• Computerised Polygraph Charts
• Behavioural Indicators
• Standardised Scoring Systems
• Comparative Physiological Analysis

The examiner then professionally interprets and evaluates the findings.

4. Final Professional Opinion

After the analytical process is completed, the examiner provides a neutral professional opinion based on the examination findings.

Results may generally be categorised as:

• Truthfulness Indicative
• Deception Indicative
• Inconclusive
• Incomplete Examination

Areas of Use of Polygraph Examination

Polygraph examinations are used in many countries for investigative and truth-verification purposes, including:

• Suspicion Verification
• Marital and Relationship Disputes
• Infidelity Investigations
• Family Dispute Resolution
• Corporate Fraud Investigations
• Employee Screening
• Workplace Misconduct Investigations
• Criminal Investigations
• Legal & Investigative Support Assessments
• Internal Fraud Investigations
• Pre-Employment Screening
• Theft or Betrayal Related Matters

Is Polygraph Evidence Admissible in Court?

Polygraph testing is still relatively new in Bangladesh, and its formal use in Bangladeshi courts has not yet been officially established. However, in neighbouring India and many other countries, polygraph examinations are used as investigative support tools and interrogation-assistance techniques.

Countries including the United States, Mexico, Russia, Israel, South Africa, Ukraine, Japan, and India use polygraph examinations in various investigative and forensic contexts.

In India, Polygraph, Layered Voice Analysis (LVA), and Brain Mapping are regularly used by various Forensic Science Departments, Forensic Science Laboratories (FSL), and investigative agencies.

Although polygraph reports are generally not considered standalone or conclusive legal evidence, they are widely used as supportive investigative tools to assist in investigations, behavioral assessments, and truth-verification processes.

Polygraph findings should always be evaluated alongside other evidence, investigations, and forensic analyses.

Personal & Corporate Use in Bangladesh

Globally, polygraph examinations are used in corporate investigations, internal fraud investigations, pre-employment screening, marital disputes, theft-related matters, and behavioral investigations.

In Bangladesh, there is currently no specific legal prohibition against conducting such examinations when performed professionally, ethically, and with informed consent.

Use of Additional Forensic Technologies

In addition to Polygraph Examination, we also advocate and work with modern forensic and behavioural assessment technologies such as:

• Layered Voice Analysis (LVA)
• Brain Mapping
• Psychological Profiling
• Behavioural Observation
• Investigative Interviewing

Over the past several years, we have provided technical support and professional consultation on these subjects to various Government Agencies and Law Enforcement Organizations.

Use Beyond Law Enforcement Agencies

Polygraph examinations are not limited to CID or DB only. Around the world, private investigation agencies, corporate security units, and forensic consultancy organisations also use polygraph examinations.

Important Scientific & Legal Limitations

Polygraph testing is a supportive forensic assessment method. For sensitive matters, additional support may be required through:

• Digital Forensics
• Cyber Investigation
• Behavioural Investigation
• Documentary Evidence
• Witness Statements
• Other forensic analyses

Voluntary Participation Policy

Participation in any polygraph examination must be completely voluntary. We take the signature of participants on a 300 taka government stamp that he/ she is willing and self-voluntary participants in the polygraph. No examination is conducted through coercion, pressure, or unlawful means.

Prior to examination, informed consent is obtained regarding:

• Interview Procedures
• Psychological Profiling
• Polygraph Examination
• Recording & Documentation

Confidentiality Policy

All examination records, reports, interview materials, and analytical information are maintained confidentially according to professional forensic and ethical standards.

The institution’s internal procedures, scoring systems, and forensic frameworks are considered intellectual property.

Recording & Documentation Policy

For professional, security, and documentation purposes, video, audio, behavioural, and analytical recordings may be conducted during the examination process.

These materials remain institutional property and may be securely preserved for professional and legal documentation purposes.

Health & Physical Condition Requirements

Examinees must disclose important conditions, including:

• Neurological Disorders
• Mental Health Conditions
• Heart Disease or Physical Complications
• Medication Usage
• Drug or Alcohol Consumption

Failure to disclose such information may affect examination accuracy.

Countermeasure & Non-Cooperation Policy

Attempts to manipulate physiological responses, conceal information, or obstruct the examination process may result in:

• Cancellation of the Examination
• Classification as Incomplete Examination
• Refusal of Re-Examination

Polygraph Examination Fee

BDT 50,000 only

The fee includes:

• Psychological Profiling
• Body Language Analysis
• Pre-Test Interview
• Polygraph Examination
• Data Analysis
• Final Professional Opinion Report

Payment Policy

• Full payment must be completed before the examination
• Fees are completely non-refundable

Who Conducts the Polygraph Examination?

Polygraph examinations are conducted by trained and certified professionals with expertise in:

• Forensic Psychology
• Human Behavioral Analysis
• Investigative Interviewing
• Scientific Lie Detection
• Psychological Assessment

To ensure accurate results and professional standards, examinations should be conducted by internationally trained and experienced Polygraph Examiners, which is provided in Bangladesh by BIFPS Consultancy Ltd. (ForensicBD).

Lead Polygraph Examiner

Md Meraz Hossain

• PhD Scholar in Forensic Psychology, National Forensic Sciences University, India
• MSc in Clinical & Counselling Psychology, Jagannath University, Dhaka
• BSc in Psychology, Jagannath University
• PGT in Psychotherapy, BSMMU, Bangladesh
• Addiction Professional (DNC), Dhaka
• Certified NLP Trainer & Life Coach
• CBT Trainer & Corporate Trainer
• Graphologist (Handwriting Analysis Expert)
• Forensic Document Examiner
• Body Language Analyst
• Lie Detection (Polygraph) Examiner
• Private Investigator
• SEAH Investigator
• Former Guest Lecturer, Govt. Titumir College, Dhaka
• Trainer for Military, Police & Intelligence Agencies, Bangladesh
• Managing Director, Bangladesh Institute of Forensic Psychology & Sciences; BIFPS Consultancy Ltd.

He works in the fields of forensic behavioral analysis, deception detection, psychological assessment, investigative interviewing, and scientific truth-verification methodologies. Through multidisciplinary forensic approaches, he provides investigative, behavioral assessment, and forensic support services.

Ethics & Professional Commitment

All examinations are conducted in accordance with professional forensic ethics, institutional protocols, and applicable laws.

BIFPS Consultancy Ltd. (ForensicBD) reserves the right to refuse or terminate any examination under any circumstances.

Final Disclaimer

Polygraph testing is a scientific, analytical, and supportive forensic assessment method designed to assist truth-verification processes through physiological and psychological analysis.

However, polygraph examination should not be considered the sole or absolute determinant of truth, deception, guilt, or innocence. In many situations, additional supporting evidence and forensic analyses may also play an important role.