Section 40 Bharatiya Sakshya Adhiniyam, 2023: Facts bearing upon opinions of experts

Section 40 of Bharatiya Sakshya Adhiniyam, 2023: Facts bearing upon opinions of experts

Official Bare Act Text

Override / Mandate Mens Rea (Intent) Actus Reus (Conduct) Punishment Limitation Monetary

Facts, not otherwise relevant, are relevant if they support or are inconsistent with the opinions of experts, when such opinions are relevant.

Illustrations

(a) The question is, whether A was poisoned by a certain poison. The fact that other persons, who were poisoned by that poison, exhibited certain symptoms which experts affirm or deny to be the symptoms of that poison, is relevant.

(b) The question is, whether an obstruction to a harbour is caused by a certain sea-wall. The fact that other harbours similarly situated in other respects, but where there were no such sea-walls, began to be obstructed at about the same time, is relevant.

Statutory Defined Terms in this Section: (Click any term for official legal definition)

Court Sec 2(1)(a)

Legal Commentary & Landmark Judgments: Section 40

Section 40 regulates facts bearing upon the opinions of experts, declaring that facts not otherwise relevant are relevant if they support or are inconsistent with the opinions of experts.

Corroboration of Expert Opinion: Allows introduction of empirical experiments, medical test charts, or chemical control samples that corroborate the expert's conclusion.
Contradiction & Impeachment: Authorizes adverse counsel to lead facts, clinical test results, or metallurgical analyses that contradict the foundation of the expert witness's testimony.
Scientific Consistency: Ensures that expert hypotheses are tested against objective factual evidence and scientific methodology.

Key Landmark Precedents:

Murari Lal v. State of M.P. (1980) 1 SCC 704: The Supreme Court observed that the science of handwriting comparison is imperfect; expert opinion must be tested against surrounding facts and corroborative circumstances under Section 46 IEA (Section 40 BSA).
State of H.P. v. Jai Lal (1999) 7 SCC 280: Held that an expert must furnish the scientific data and objective criteria supporting their opinion so the court can independently verify its soundness.

Courtroom Practice & Strategic Litigation Guidance:

In medical negligence and forensic toxicology cases, introduce conflicting laboratory test logs, calibration records of testing apparatus, or international peer-reviewed protocols under Section 40 to impeach an adverse expert's conclusions.