LHC acquits man in murder case, says polygraph test invalid without consent

LAHORE (Muhammad Ashfaq) – The Lahore High Court has acquitted a man sentenced to life imprisonment in a murder case, citing doubts over the polygraph test and other evidence. Justice Ali Zia Bajwa ruled that a polygraph test cannot be conducted without the voluntary consent of the accused.

Justice Ali Zia Bajwa issued a 19-page verdict on the appeal filed by Muhammad Imran. In the judgment, the court noted that the prosecution relied on the polygraph test to strengthen its case, even though polygraphy measures physical reactions such as heart rate, blood pressure, breathing, and sweating to detect lies, and raises serious constitutional concerns under Article 13(b), which protects the right to remain silent.

The court stated that extracting confessions or information through physical, mental, or psychological pressure amounts to coercion, and the state cannot obtain confessions through force, deception, or scientific methods like polygraphy.

The judgment further stated that while fingerprints and DNA may be collected as physical evidence, mental impressions cannot be forcibly obtained. Although the polygraph test measures physical reactions, it still requires verbal responses, which makes it unreliable. The results also have a significant chance of error, and emotional factors such as stress, fear, or depression can make an innocent person seem guilty, while someone lying may hide deception through controlled breathing or slight body movements.

A polygraph test may indicate truthfulness but cannot alone prove a crime.

The court laid down guidelines, stating that the accused must express consent before a judicial magistrate, and the magistrate must ensure that the accused is in judicial custody when giving consent. Consent given during police remand would not be acceptable, and the test must be conducted under the supervision of qualified officials of the Punjab Forensic Science Agency. The accused also has the right to withdraw consent at any time.

The judgment noted that the polygraph test conducted in this case contained several illegalities and was done without the free will of the accused. In cases where there are no eyewitnesses, the prosecution must prove every link in the chain of evidence, but in this case it failed to do so. The court accepted the appeal and acquitted Muhammad Imran, who had been sentenced to life imprisonment and fined by a Lahore Additional Sessions Judge in 2020.