Accused's Consent Before Magistrate Is Mandatory For Polygraph Test — Even When Not In Custody: Punjab & Haryana High Court

"Consent Of The Accused, Whether In Custody Or Outside Custody, Is A Sine Qua Non For The Making Of A Valid Polygraph Test" — In a significant ruling that settles a contested question in forensic evidence law, the Punjab and Haryana High Court has held that the requirement of obtaining prior consent of an accused before a Magistrate — as a precondition to conducting a polygraph test — applies equally whether the accused is in custody or at liberty. The CBI's argument that no such consent was needed since the accused were outside custody at the time of the polygraph examination was firmly rejected as "an extremely frail argument."

The ruling came in the context of the sensational Ranjit Singh murder case involving Baba Gurmeet Ram Rahim Singh, Chief of Dera Sacha Sauda, Sirsa, and co-accused, where the Division Bench of Justice Sureshwar Thakur and Justice Lalit Batra acquitted all appellants on May 28, 2024, setting aside life imprisonment convictions recorded by the Special CBI Court, Panchkula.

The court further held that even where a polygraph test yields "deceptive answers" from the accused, such results carry no independent evidentiary value unless they are clinchingly corroborated through effective recoveries under Section 27 of the Indian Evidence Act, 1872. In the absence of such corroboration, polygraph results "loose their evidentiary potency" and cannot be used to sustain a conviction.

Accused Nos. 2, 5, and 6 in the Ranjit Singh murder case — being Avtar Singh, Krishan Lal, and Sabdil Singh respectively — were subjected to polygraph tests by the CBI between July 18 and July 21, 2005. The examination was conducted while these accused were not in judicial or police custody. The polygraph report revealed that there were "some deceptive answers" meted to relevant queries put to the accused during the test.

The CBI relied upon these polygraph results as part of the corroborative evidence against the accused, urging the court that the test results buttressed the prosecution's case of a criminal conspiracy to murder Ranjit Singh. The appellants challenged the validity and evidentiary worth of these results on two distinct grounds: first, that no prior consent of the accused before a Magistrate had been obtained before conducting the test; and second, that even if the results were accepted, they constituted only corroborative and not substantive evidence, requiring clinching corroboration to have any legal effect.

The two central legal questions on the polygraph point were: (i) whether the mandatory consent of the accused before a Magistrate, as a precondition for a valid polygraph test, is confined only to situations where the accused is in custody; and (ii) whether polygraph test results showing deceptive answers possess sufficient evidentiary potency to corroborate a conviction, particularly in the absence of recoveries under Section 27 of the Indian Evidence Act.

On Whether Consent Is Confined to Custody

The court decisively rejected the CBI's argument. Examining the law laid down in Smt. Selvi's case, the bench held that the Selvi judgment "is nowhere stated, that the consent of the accused be ensured to be taken for therebys a polygraph test becoming made upon the accused concerned, thus only when the accused is in custody."

Reading the Selvi ruling in its entirety and natural import, the court declared: "In other words, the consent of the accused concerned, whether in custody or is outside custody, rather is a sine qua non for the makings of a valid polygraph test upon the accused concerned."

The significance of this holding is considerable. It categorically forecloses any attempt by investigating agencies to circumvent the protection of prior Magisterial consent by choosing to administer polygraph tests during a window when the accused is at large — whether on bail, before arrest, or during the period of investigation prior to custodial remand. The protection, the court held, attaches to the person of the accused by virtue of the test being conducted upon them, not by virtue of their custodial status.

On The Evidentiary Worth of Polygraph Results — Not a Perfect Science

Even proceeding beyond the consent issue, the court held that the polygraph results in the present case could not sustain any evidentiary weight for an additional and equally fundamental reason: the complete absence of corroborating recoveries under Section 27 of the Indian Evidence Act.

The court noted that it is well established — and was stated both in the Selvi judgment as well as in the deposition of the CBI's own expert witness PW-15 — "that the said polygraph test is not a perfect science, and, the results of the said test do require clinching corroborations theretos rather becoming meted through recoveries in accordance with Section 27 of the Indian Evidence Act, 1872 thus becoming effected."

In the present case, the prosecution had entirely failed to produce any such clinching corroboration. There were no recoveries of any weapon of offence at the instance of the accused, no disclosure statements leading to discoverable facts, and the other incriminatory material on record had already been found by the court to be "of an extremely tenuous nature." In consequence, the court held: "Resultantly, when there is neither any clinching corroboration to the purported deceptively made answers by the accused(s) who underwent the polygraph test, especially from any efficacious recoveries becoming effected nor through other incriminatory material which otherwise has been stated (supra) rather to be of an extremely tenuous nature. Resultantly, the results of the said polygraph test, loose their evidentiary potency."

On the Broader Principle: Polygraph as Corroborative, Not Substantive Evidence

The court's ruling also reinforces the established position that polygraph test results can, at best, be corroborative evidence — they cannot constitute substantive evidence of guilt. The appellants' counsel had correctly submitted that even if the results were admitted, they were not to be "construed to be substantive evidence." The court's finding goes a step further in holding that even as corroborative evidence, polygraph results are of no legal value unless they are independently confirmed through tangible material like recoveries under Section 27. In other words, a "deceptive answer" in a polygraph test, standing alone and unconfirmed by any physical or forensic corroboration, is legally inert.

The Punjab and Haryana High Court's ruling adds important clarity to Indian forensic evidence law. Investigating agencies, particularly central investigative bodies like the CBI, must take note that the safeguard of obtaining prior free and informed consent of the accused before a Magistrate — as mandated by the Supreme Court in Smt. Selvi's case — cannot be bypassed on the technical ground that the accused was not in custody at the time of the test. The consent requirement is universal in its application and goes to the root of the validity of the entire polygraph exercise.

Further, for polygraph results to carry any evidentiary weight whatsoever — even as corroboration — they must be buttressed by clinching recoveries or other cogent material under Section 27 of the Indian Evidence Act. A polygraph result reporting deceptive answers, without more, does not incriminate an accused in the eyes of the law.