Gauhati High Court Overturns Murder Conviction, Cites Unsound Mind and Prosecution Lapses

Itanagar, Arunachal Pradesh - The Gauhati High Court, Itanagar Bench, comprising Justice Kalyan Rai Surana and Justice Mridul Kumar Kalita , has acquitted Tayum Biku of murder, grievous hurt, and criminal trespass charges, overturning a 2013 Sessions Court conviction. The High Court's decision, delivered on June 11, 2025, hinged on the appellant's plea of unsoundness of mind under Section 84 of the Indian Penal Code (IPC) and significant deficiencies in the prosecution's case, which relied heavily on circumstantial evidence.

Case Background: A Morning of Mayhem

The case dates back to September 8, 2006, when Yingkiong Police Station received information about an unidentified person indiscriminately attacking people with a dao (machete). The rampage resulted in the death of Laxmi Sonar and grievous injuries to six others, including Obi Peyang, Neri Peyang , Keten Lipir, Onu Tali, Bonu Gammeng, and Nokul Gop.

Tayum Biku was arrested the same day, and two daos were recovered from his possession. The Sessions Judge, Pasighat, subsequently convicted Biku under Sections 302 (murder), 326 (voluntarily causing grievous hurt by dangerous weapons), and 447 (criminal trespass) of the IPC, sentencing him to life imprisonment for murder, among other concurrent sentences.

An appeal (Crl.A. 1/2022) was filed by Obit Biku on behalf of the convict, Tayum Biku . The High Court, while noting that a relative cannot typically file an appeal for a convict, treated the appeal as filed by Tayum Biku himself.

Appellant's Plea: Unsoundness of Mind and Flawed Investigation

Mr. L. Perme, counsel for the appellant, primarily argued that Tayum Biku was suffering from unsoundness of mind at the time of the incident, rendering him incapable of understanding the nature of his acts, a defence covered under Section 84 IPC. Key submissions included:

* History of Mental Issues : Statements recorded under Sections 161 and 164 CrPC indicated Biku 's disturbed mental state, including feelings of persecution and a lack of memory of the events.

* Defence Witnesses : Four defence witnesses, including a psychiatrist (DW-3, Dr. Ajit Kumar Biswas ), testified to Biku 's history of mental illness. DW-3 diagnosed him with Paranoid Schizophrenia in 2014, noting symptoms consistent with his condition around the time of the offence.

* Investigative Lapses : The Investigating Officer (IO) failed to subject Biku to a mental health examination despite clear indications of mental disturbance. The initial medical report post-arrest only commented on physical fitness.

* Lack of Mens Rea and Evidence Gaps : No motive was established. Critical eyewitnesses to the murder of Laxmi Sonar were not examined, and the weapon of offence was not subjected to a serological test to link it conclusively to the crime. The circumstantial evidence, it was argued, did not form a complete chain.

Prosecution's Defence of Conviction

Ms. L. Hage, Additional Public Prosecutor, contended that the trial court's conviction was sound. She argued:

* Unreliable Defence : The psychiatrist examined Biku years after the incident, and there was no prior government medical record of his alleged mental illness.

* Awareness of Actions : Biku was found healthy post-arrest and his act of hiding suggested awareness of wrongdoing.

* Eyewitness Testimony : Some victims had identified Biku as the assailant. She did, however, concede that the forensic examination report for the weapon was not collected or exhibited during the trial.

High Court's Scrutiny and Findings

The High Court meticulously reviewed the evidence and arguments.

Shortcomings in Prosecution Evidence

The Court noted that only two victims, Obi Peyang (PW-4) and Keten Lipir (PW-7), specifically named Tayum Biku as their attacker. Other injured witnesses did not identify him in court. Crucially, the alleged eyewitness to the murder of Laxmi Sonar , Mr. Sanet Barman, was not examined.

The Court highlighted the principles for cases based on circumstantial evidence, as laid down in Sharad Birdhichand Sarda Vs. State of Maharashtra , emphasizing that circumstances "must or should be" and not merely "may be" established. It found that the prosecution failed to fully establish the chain of evidence linking Biku to the murder of Laxmi Sonar beyond a reasonable doubt. The judgment stated: > "Thus, though the evidence on record indicates that PW-4 and PW-7 were assaulted by the appellant and there is a strong probability that it was the appellant only, who had assaulted Laxmi Sonar resulting in her death. However, the evidence adduced during the trial falls short of fully establishing the fact that it was the appellant only, who assaulted Laxmi Sonar resulting in her death."

The absence of a serological report for the seized daos and the failure of independent witnesses to identify them further weakened the prosecution's case.

Upholding the Plea of Unsoundness of Mind (Section 84 IPC)

The Court gave significant weight to the appellant's plea of insanity. Key observations included:

* Lack of Motive : The random nature of the attacks without apparent motive pointed towards a disturbed mental state.

* Appellant's Statements : Biku 's early statements under S.164 CrPC, describing fear, persecution, and memory loss, were indicative of mental unsoundness.

* Investigative Duty : Citing Bapu Alias Gujraj Singh Vs. State of Rajasthan , the Court underscored the IO's duty to conduct a medical examination for mental soundness when such a history or indication arises. The judgment noted: > "The lapse on the part of the Investigating Officer in not doing so creates a serious infirmity in the prosecution case and benefit of doubt, on that account has to be given to the appellant."

* Defence Evidence on Insanity : The Court found that the trial court erred in discarding the testimony of defence witnesses. It referred to Prakash Nayi Alias Sen Vs. State of Goa , affirming that the burden on the accused to prove insanity under Section 84 IPC is based on a "preponderance of probability." The evidence from DW-3 (psychiatrist) and other defence witnesses, suggested a history of mental illness consistent with the appellant's state during the incident.

The Court concluded: > "We are of the considered opinion that there are sufficient materials on record to come to the conclusion by applying the principle of the preponderance of probability that the appellant was suffering from unsoundness of mind indicating to the fact that due to the reason of unsoundness of mind, he was incapable of knowing the nature of the act of that what he was doing was wrong and contrary to law."

The Verdict: Acquittal and Directions for Mental Healthcare

Based on these findings, the Gauhati High Court allowed the appeal, set aside the trial court's judgment and order of conviction and sentence. Tayum Biku was acquitted of all charges.

Significantly, the Court, invoking its parens patriae jurisdiction, directed the Deputy Commissioner of Lower Subansiri District, Arunachal Pradesh, to: > "...take all necessary steps for getting the appellant medically examined and thereafter, if required, provide him proper mental health care and treatment from mental health services run or funded by the Government under the provisions of the Mental Healthcare Act, 2017."

This directive acknowledges the appellant's diagnosed condition of paranoid schizophrenia and ensures he receives necessary care, even post-acquittal. The judgment underscores the judiciary's role in not only adjudicating guilt but also ensuring the welfare of individuals with mental health conditions within the legal system.