Kuala Lumpur: Polygraphs are used by law enforcement agencies, the judicial system, the private sector and the media in some countries to determine if a person is telling the truth.

A polygraph test should be made a prerequisite for such posts so that potential employers could assess the candidates to see if they were fit to deal with huge sums of money, national secrets, matters of national security or even sexual harassment or violent, infidelity,corruption and other offences that could not be corroborated with physical evidence.

Polygraphs measure physiological changes from three systems in people’s blood pressure, respiration and electro dermal response (palmar sweating or galvanic skin response in some form since 2016.

The polygraph test involved three stages: the pre-testing stage, testing stage and post-testing stage.
The pre-testing stage is when the subject is interviewed on his background, followed by the construction of questions. Depending on the issue or case, this stage takes about one to two hours.

The testing stage is when the subject sits on a special chair and answers “Yes” or “No” to questions. This involves three examinations consisting of at least 10 questions.

During the post-testing stage, there will be a diagnostic analysis and interrogation. There are numerous examples where the polygraph has led to a breakthrough or a confession.

But the whole three stages take a few hours, depending on the skill of examiners and the complexity of the cases.

The polygraph instrument produces only graphs. The examiners determine whether the person is deceptive or truthful. The qualified examiners are the “lie detectors” and truth verifiers and not the polygraph instrument.

The lying will produce physiological changes that polygraph examiner will be able to interpret these signs accurately and differentiate between the patterns of the graphs in an honest examinee’s nervousness from deception. He is capable to determine when an examinee engages in behaviours to distort the polygraph tracing and influence the test results.

However, to ensure and maintain integrity, the tests have to be conducted randomly. It is a preventive measure as employees will think twice before committing an offence, knowing that they could, at any time, be made to sit for the test. This is the beauty of the polygraph tests.

The American Polygraph Association(APA)has conducted over 250 studies which showed the reliability and accuracy of the polygraph is high. It is 98 percent accurate under good hands, using right questions, validated techniques, special room and chair, empirically based manual scoring and examined by certified polygraph examiners.

In Singapore, the police, the Corrupt Practices Investigation Bureau, the Ministry of Manpower, the Prisons Department, Customs, the Central Narcotics Bureau, Security and Intelligence agencies, and the military use it for personnel screening and investigations.

The Singapore prosecutor’s office also uses it in decision making whether or not to file charges while in Taiwan, a judge would subject an accused to a polygraph test prior to sentencing.

Agencies like the CIA, FBI, National Security Agency, US Secret Service, and the US Department of Defence, and the majority of US police departments use polygraph tests in recruitments and investigations or to determine links with terrorist activities.

In England and Wales, polygraph tests are used by the police in the monitoring of released sex offenders.
A few years ago, the Malaysian Anti-Corruption Commission(MACC) chief commissioner Azam Baki said the Public Service Commission (PSC) should consider making polygraph tests part of its recruitment policy, applying for posts within the management and professional groups, as these would comprise individuals who would be filling critical positions in public agencies.

He said only then could the service arrest the problem of corruption plaguing the sector and if the tests were reintroduced, it would augur well for the integrity of the sector as those with corrupt tendencies would be red-flagged from the start.

The former Director-General of the National Centre for Governance, Integrity, and Anti-Corruption, Tan Sri Abu Kassim Mohamed, stressed that the polygraph test can be used as evidence in a court case when administered by qualified examiners, but it is up to the judiciary to determine it.

President of the Shariah Lawyers Association, Musa Awang, said that based on existing law, the polygraph tests may be used as evidence in court but ultimately it is the judge who has the right to accept it or not.

As a result, the Chief Justice TunTengku Maimun Tuan stated that the judiciary is studying a proposal to use the results of polygraph tests as evidence in court but would involve amendments of Evidence Act 1950.

Currently, there is no precedent on the admissibility of polygraph evidence in Malaysia and Singapore except Malaysian’s civil court accepted polygraph as part of evidence in an insurance fraud case. The MACC, police, army and some companies are using polygraph for screenings and investigations.

If you ask how reliable and trustworthy a polygraph is — the answer: it is better than nothing.


Datuk Seri Akhbar Satar holds the professorial chair and director at Institute of Crime and Criminology(ICC), HELP University and a polygraph examiner.

** The views and opinions expressed in this article are those of the author(s) and do not necessarily reflect the position of Astro AWANI.