POLYGRAPHS are used in some countries to determine if a person is telling the truth.
Employers should make a polygraph test a prerequisite for hiring someone. The test can assess candidates to see if they are fit to deal with huge sums of money, national secrets, matters of national security, sexual harassment, violence, infidelity, corruption and other offences that cannot be corroborated with physical evidence.
Polygraphs measure physiological changes in three systems in people: blood pressure, respiration and electrodermal response (palmar sweating or galvanic skin response in some form since 2016). A polygraph examination involves a 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. The testing stage is when the subject answers "yes" or "no" to questions, involving three examinations of at least 10 questions.
During the post-testing stage, there will be a diagnostic analysis and interrogation. There are numerous examples of the polygraph leading to a breakthrough or a confession. The 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 — not the polygraph instrument — are the "lie detectors" and truth verifiers.
Lying will produce physiological changes that polygraph examiners can interpret accurately in patterns of the graphs. He can determine when an examinee engages in behaviour to distort the polygraph tracing and influence the results.
To ensure and maintain integrity, the tests have to be conducted randomly. They can also be a preventive measure as employees will think twice before committing an offence, knowing that they could, at any time, be subject to the test. This is the beauty of polygraph tests.
The American Polygraph Association has conducted over 250 studies which showed the reliability of the polygraph. It is 98 per cent accurate in good hands, using the 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, Manpower Ministry, Prisons Department, Customs, the Central Narcotics Bureau, intelligence agencies and the military use it for personnel screening and investigations. The prosecutor's office also uses it to decide whether to file charges.
In Taiwan, a judge would subject an accused to a polygraph test prior to sentencing.
United States agencies like the Central Intelligence Agency, Federal Bureau of Investigation, National Security Agency, Secret Service, and the Department of Defence, and the majority of its police departments use polygraph tests in recruitments and investigations.
In England and Wales, polygraph tests are used by the police to monitor released sex offenders.
A few years ago, Malaysian Anti-Corruption Commission (MACC) Chief Commissioner Tan Sri Azam Baki said the Public Service Commission should consider making polygraph tests part of its recruitment process for management and professional service schemes, as these comprised critical positions in public agencies.
He said this could help arrest the problem of corruption in the civil service as those with corrupt tendencies would be flagged from the start.
Former director-general of the National Centre for Governance, Integrity and Anti-Corruption, Tan Sri Abu Kassim Mohamed, said the polygraph test administered by qualified examiners could be used as evidence in court. But it is up to the judiciary to decide this.
Syariah Lawyers Association president Musa Awang said the law allows polygraph tests to be used as evidence in court but it is the judge who decides whether to accept it or not.
As a result, Chief Justice Tun Tengku Maimun Tuan Mat said the judiciary is studying if polygraph tests can be admitted as evidence in court, and that this will involve amending the Evidence Act 1950.
Currently, there is no precedent on the admissibility of polygraph evidence in Malaysia and Singapore. However, in a Malaysian insurance fraud case, the court accepted polygraph results as part of the evidence. The MACC, police, army and some companies are using polygraphs for screenings and investigations.
How reliable and trustworthy is a polygraph? It is better than nothing.
The writer holds the professorial chair and is director at Institute of Crime and Criminology, HELP University and a polygraph examiner