“The Trajectory-Consistency Rule” – Supreme Court clarifies limits of relying on post-offence conduct in circumstantial murder cases
(Commentary on Vaibhav v. State of Maharashtra, 2025 INSC 800)

1. Introduction

The Supreme Court’s decision in Vaibhav v. State of Maharashtra (2025) re-examines the evidentiary architecture of circumstantial homicide prosecutions. The appellant, a first-year student, was convicted of murdering his classmate Mangesh with his police-officer father’s service pistol. Both the Trial Court and the Bombay High Court treated Vaibhav’s post-incident behaviour—shifting the body, cleaning the scene and feigning ignorance—as the decisive link evidencing mens rea. The Supreme Court, speaking through Satish Chandra Sharma, J., sets aside the murder and Arms Act convictions, retaining only the Section 201 IPC conviction for tampering with evidence.

The judgment establishes a significant precedent: when a prosecution is solely circumstantial, inconsistent ballistic/medical evidence breaks the chain even if the accused’s conduct is highly suspicious. This commentary labels the principle the “Trajectory-Consistency Rule.”

2. Overview of Facts & Issues

• Parties: Vaibhav (appellant/accused) and the State of Maharashtra (respondent).
• Incident (16-09-2010): Vaibhav and Mangesh leave college together, reach Vaibhav’s house; Mangesh is later found dead of single gunshot injury from a 9 mm service pistol allotted to Vaibhav’s father (PW-12).
• Prosecution theory: Vaibhav intentionally shot Mangesh, concealed evidence, enlisted friends for disposal.
• Defence theory: Accidental self-infliction—Mangesh examined the pistol, looking down the barrel, the gun discharged; panic led Vaibhav to hide evidence.
• Principal issues before the Supreme Court:
  • Whether the circumstantial chain proved homicide beyond reasonable doubt.
  • Whether ballistic trajectory and medical evidence created reasonable doubt.
  • Weight of post-offence conduct under Section 8 Evidence Act vis-à-vis prosecution’s primary burden.

3. Summary of the Judgment

The Court partially allowed the appeal:

• Murder (Section 302 IPC) & Arms Act (S.5/25): Convictions quashed—prosecution failed to prove who pulled the trigger; ballistic trajectory compatible with accidental firing.
• Destruction of Evidence (Section 201 IPC): Conviction sustained—Vaibhav admittedly removed the body and cleaned the scene; sentence limited to period already undergone.

Central to acquittal was the Court’s finding that the bullet’s entry through the eye, exit through lower occipital bone, and subsequent upward strike on a high ventilator was never reconciled with the prosecution version of a straight frontal homicide. This “trajectory incongruity,” untested fingerprints, and absence of motive generated a reasonable alternative hypothesis of accident, compelling acquittal on major charges.

4. Detailed Analysis

4.1 Precedents Cited and Their Influence

• Anwar Ali v. State of H.P. (2020): Reiterated that absence of motive weighs for accused in circumstantial cases. Relied upon to highlight complete lack of animus between friends.
• Babu v. State Of Kerala (2010) & Kishanpal (2008): Distinguished importance of motive in circumstantial vs direct evidence; cited to show courts must cautiously treat motive deficiency.
• Shivaji Chintappa Patil v. State Of Maharashtra (2021): Confirmed motive as “important link” in circumstantial evidence—used to underscore prosecution’s failure to establish motive.
• Nandu Singh v. State of M.P. (2022): Affirmed that complete absence of motive tilts balance towards accused; served as immediate authority for acquittal.
• Older Section 8 Evidence Act jurisprudence: Court cites these to define admissibility of conduct but warns such conduct cannot replace affirmative proof of actus reus.

4.2 Core Legal Reasoning (“Trajectory-Consistency Rule”)

1. Burden Hierarchy: Prosecution must first prove guilt beyond reasonable doubt; only thereafter does burden shift to accused to explain conduct. Trial and High Court reversed this sequence by letting accused’s silence plug evidentiary gaps (¶21-22).
2. Ballistic/Medical Primacy: For gunshot deaths, the direction, distance, number and aftermath of bullet wounds are objective scientific indicators. Any hypothesis inconsistent with these physical facts is untenable. Here the upward post-exit trajectory contradicted homicide theory (¶17-19).
3. Section 8 Evidence Act Limits: Accused’s flight, concealment or deceit are relevant but only as corroborative. They cannot supplant the missing causal link of who fired (¶21). Over-reliance on such conduct risks conviction on suspicion.
4. Motive Vacuum: Two friends with no prior animosity reduce probability of intentional killing; when objective forensic evidence also doubts prosecution, benefit must go to accused (¶25).
5. Alternative Hypothesis Test: If two plausible views exist, court must adopt one favourable to accused. Here, accidental discharge was held “fairly probable” and supported by forensic data (¶28-29).

4.3 Potential Impact of the Judgment

• Investigation Standards: Police must obtain ballistic reports, trajectory reconstruction and fingerprint testing in every firearm homicide; absence will now be fatal when defence alleges accident/suicide.
• Trial Courts’ Approach: Judges must explicitly reconcile medical science with circumstantial links before drawing inference from conduct; failure could invite appellate reversal.
• Section 8 Evidence Act Usage: Narrows scope—post-offence conduct gains weight only after independent evidence identifies actus reus. This curtails the practice of conviction by behaviour.
• Defence Strategy: Encourages early introduction of forensic-based alternative explanations; emphasises calling of expert witnesses.
• Arms Act Prosecutions: Prosecution must prove use of firearm by accused, not mere presence at scene. Fingerprint/DNA on weapon may become routine.
• Academic Doctrine: The “Trajectory-Consistency Rule” may enter criminal-law syllabi: in firearm fatalities, absence of trajectory congruence generates reasonable doubt notwithstanding suspicious behaviour.

5. Complex Concepts Simplified

• Circumstantial Evidence: Chain of separate facts (e.g., last-seen, motive, weapon recovery) which, when connected, point to guilt. All links must be intact; if one is missing, chain breaks.
• Section 8 Evidence Act: Makes conduct (before, during, after event) a relevant fact. However, relevance ≠ proof; conduct is collateral unless coupled with substantive evidence.
• Burden of Proof Standards:
  • Prosecution: Beyond reasonable doubt (≈ 95-99% certainty).
  • Accused: Preponderance of probabilities (just >50%).
• Ballistic Trajectory: Path travelled by bullet—from muzzle to entry wound, through body, to exit and final impact. Incongruent angles/directions may suggest alternative firing positions or modes (accident/suicide).
• Section 201 IPC: Punishes causing disappearance of evidence or giving false information knowing or having reason to believe that an offence has been committed. Mens rea relates to hindering investigation, not causing crime.

6. Conclusion

Vaibhav re-centres forensic science in Indian criminal adjudication. The Supreme Court reminds courts that while human behaviour may raise eyebrows, convictions demand objective harmony between scientific evidence and circumstantial links. By refusing to let post-offence conduct substitute for the missing ballistic link, the Court lays down the Trajectory-Consistency Rule: Where bullet behaviour contradicts prosecution narrative, the chain is broken, and suspicion—however grave—cannot convict.

Looking ahead, investigators must meticulously document bullet paths and trial courts must rigorously analyse such evidence before recording guilt in firearm deaths hinged on circumstantial proof. The judgment thus fortifies the foundational criminal-law credo: “It is better that ten guilty persons escape than that one innocent suffer.”