As criminal investigations increasingly rely on scientific and technological tools, courts are repeatedly confronted with a fundamental constitutional dilemma, can the pursuit of truth justify methods that compromise individual rights? While modern forensic techniques promise efficiency and objectivity, their unchecked use risks eroding the foundational principles of criminal justice. This tension was squarely addressed by the Lahore High Court in Muhammad Imran alias Gochhi v. The State, a judgment that reaffirms a central constitutional truth, technological advancement cannot displace legality, nor can scientific appeal override the presumption of innocence. The case serves as a critical intervention in Pakistan’s particularly concerning the legal status of polygraph examinations and other investigative tools rooted in scientific uncertainty.
Factual Background: When Circumstantial Evidence Failed Constitutional Scrutiny
The prosecution’s case was built entirely on circumstantial evidence. It attempted to prove guilt by presenting what it called an “unbroken chain” of facts, including last-seen evidence, CCTV footage, alleged recoveries, call data records (CDRs), and even a polygraph examination. However, when these elements were examined by the Court, the chain fell apart neither complete nor reliable. The most serious blow to the prosecution’s story came from the medical evidence. While it was alleged that the murder took place on 22 December 2019, the post-mortem report clearly showed that death had occurred almost a month later. This stark contradiction severely damaged the prosecution’s version of events and completely undermined its reliance on the last-seen theory. The Court reiterated that last-seen evidence is, by its very nature, weak and unsafe unless supported by strong and independent corroboration. The call data records were also discarded, as they lacked proper authentication and forensic verification. Through this analysis, the Court reaffirmed an essential evidentiary principle: digital evidence, given its vulnerability to manipulation, cannot be relied upon unless it strictly meets legal and forensic standards.
Polygraph Examinations and Why Courts Remain Skeptical
The most consequential aspect of the judgment lies in its rigorous examination of polygraph testing, often colloquially referred to as lie detector tests. A polygraph measures physiological responses, such as heart rate, respiration, and blood pressure, on the premise that deceptive answers trigger measurable stress responses. The Court unequivocally rejected the evidentiary reliability of this assumption. It observed that physiological responses are influenced by a range of factors, including anxiety, fear, psychological vulnerability, and external stressors. As a result, truthful individuals may appear deceptive, while deceptive individuals may not, rendering the technique scientifically unstable and legally unsafe.
Article 13(b) and the Constitutional Ban on Self-Incrimination
Anchoring its analysis in constitutional law, the Court held that polygraph examinations conducted without free and informed consent violate Article 13(b) of the Constitution, which guarantees protection against self-incrimination. Even where consent is ostensibly obtained, the Court clarified that polygraph results do not constitute admissible substantive evidence, as the examinee lacks conscious control over physiological reactions. At best, the Court noted, polygraph tests may assist investigators during preliminary inquiries. They cannot, however, be elevated to proof of guilt, nor can they be used to supplement weak or incomplete evidence. Any contrary approach would impermissibly shift the burden of proof from the prosecution to the accused.
Procedural Illegality and the Limits of Forensic Authority
The Court further condemned serious procedural irregularities in the present case. Most notably, a forensic expert recorded a confessional statement on oath, an act entirely beyond the scope of his legal authority. This procedural violation alone was sufficient to nullify the polygraph exercise. Recognizing the potential for systemic abuse, the Court issued detailed guidelines governing the conduct of polygraph examinations. These guidelines seek to ensure that forensic science remains subordinate to constitutional safeguards and does not become a mechanism for coercion or evidentiary shortcuts. At a deeper level, the judgment rejects the notion that the human body itself can be treated as a witness against the accused. Polygraph testing effectively transforms involuntary bodily responses into indicators of guilt, undermining the accused’s constitutional right to silence and the prosecution’s obligation to prove its case beyond reasonable doubt. Historically, polygraph testing emerged in the early twentieth century as an experimental investigative tool rather than a method of adjudication. Its contested scientific validity and consistent judicial resistance across jurisdictions underscore why it has never achieved acceptance as reliable legal evidence.
Why This Judgment Matters for Ordinary Citizens
In a criminal justice system grappling with investigative inefficiencies and resource constraints, unregulated reliance on techniques like polygraph testing poses serious risks. It opens the door to coercive practices, legitimizes weak investigations, and disproportionately affects individuals lacking legal awareness or social power. By reaffirming constitutional discipline, the Court has safeguarded ordinary citizens from being convicted on the basis of scientific ambiguity masquerading as certainty. The ruling reinforces that justice cannot be expedited at the expense of legality and that rights are not negotiable conveniences. The judgment also exposes a critical legislative vacuum. Pakistan lacks comprehensive statutory regulation governing polygraph examinations. If such techniques are to be used at all, they must be clearly confined to investigative assistance and regulated through express legislation that defines their scope, safeguards, and limitations. Absent such regulation, forensic tools risk distorting the evidentiary process and undermining the constitutional balance between State power and individual liberty. Importantly, this case sends a broader signal for the future. As forensic science and investigative technology continue to evolve, tools such as voice stress analysis, brain imaging, and other emerging “lie detection” techniques may claim scientific objectivity. Yet the constitutional concerns highlighted in this judgment, the protection against compelled self-incrimination, the presumption of innocence, and the need for procedural safeguards apply equally to these new technologies. Without careful regulation and judicial oversight, any tool, however sophisticated, can become a mechanism of coercion or unreliable proof, rather than a genuine aid to justice.
A Necessary Constitutional Course Correction
The Lahore High Court’s ruling delivers a decisive constitutional message: criminal adjudication is not an exercise in probability, but a process governed by legality, rights, and restraint. By rejecting unreliable forensic shortcuts and reaffirming the presumption of innocence, the Court has strengthened the integrity of Pakistan’s criminal justice system. As investigative methods continue to evolve, this judgment provides a principled framework for their constitutional containment. It affirms that the pursuit of truth cannot be separated from the manner in which it is pursued and that justice, to remain justice, must always be anchored in rights rather than results.
