The default rule of appellate criminal procedure is closure: the appeal is argued on the evidence led at trial, and neither side gets a second innings. The Bharatiya Nagarik Suraksha Sanhita, 2023 preserves a carefully bounded exception. Section 433 — the successor to Section 391 of the Code of Criminal Procedure, 1973 — empowers the appellate court, in dealing with any appeal under the chapter, to take further evidence itself, or direct it to be taken by a Magistrate or Court of Session, if it thinks additional evidence to be necessary, recording its reasons. The provision exists to prevent failures of justice, not to reward tactical omissions, and courts administer it in that spirit. This explainer covers the test, the mechanics and the recurring scenarios.
The provision and its philosophy
Section 433 BNSS is short: in dealing with any appeal under the chapter, the appellate court, if it thinks additional evidence to be necessary, shall record its reasons and may either take such evidence itself or direct it to be taken by a Magistrate or, when the appellate court is a High Court, by a Court of Session or a Magistrate; the evidence so taken is certified to the appellate court, which then disposes of the appeal. Two design choices define its philosophy. The word "necessary" makes the power exceptional — the appellate stage is not an opportunity to relitigate. And the mandatory recording of reasons disciplines its exercise, ensuring that every reopening of a closed record is a reasoned, reviewable act.
When the gate opens — and when it stays shut
Applications that succeed
Evidence genuinely unavailable at trial despite diligence · subsequent events bearing directly on guilt or sentence · formal proof of a document already on record but unexhibited · material necessary to decide a juvenility or age plea raised in appeal · scientific material whose absence leaves the court unable to do justice
Applications that fail
Gap-filling for a prosecution that chose not to examine available witnesses · defence material withheld as trial strategy · affidavits procured from witnesses resiling after conviction · attempts to convert the appeal into a second trial · vague prayers with no identified evidence or explanation for the delay
The juvenility scenario deserves separate mention because it is the one context where the gate opens widest: a claim of juvenility may be raised before any court, at any stage, and the age inquiry it triggers routinely requires documents and testimony never led at trial. Sentence-stage material — post-conviction conduct, medical condition, settlement in compoundable components — also travels through this door where it bears on the appellate court's powers.
Building the application
A Section 433 application should be constructed like the exceptional plea it is. Identify the evidence with precision — the witness and the substance of the testimony, or the document and its custodian. Explain the trial-stage absence with dates and circumstances: what was done to obtain it, why it could not be produced, when it surfaced. Connect it to necessity: show the specific issue in the appeal that cannot be justly decided without it, rather than asserting general relevance. Anticipate the prejudice objection by proposing the procedure — recording by the trial court within a fixed time, with cross-examination — so the court sees a contained exercise, not an unravelling. Oppositions mirror the structure: attack availability, diligence, authenticity and necessity, and emphasise the settled caution against permitting either side to repair its trial at the appellate stage.
Annexures that carry such applications: the proposed witness's affidavit or the document itself; proof of trial-stage efforts (summons applications, replies, correspondence); the relevant trial-record extracts showing the gap is real and material; and a draft of the precise order sought, including who records the evidence and by when.
After the evidence comes in
Once additional evidence is taken and certified, the appellate court hears the parties on the enlarged record. The outcomes span the full appellate range: confirmation where the new material changes nothing; alteration of conviction or sentence where it changes something; acquittal where it destroys a link the conviction needed; and, where the defect is structural, retrial. For counsel, the closing discipline is to argue the combined record as a whole — additional evidence rarely wins an appeal by itself; it wins by giving existing doubts a foundation the trial record alone could not supply.
The chamber of Advocate Manish Jha appears in criminal appeals and revisions before the Sessions Courts of Delhi, the High Court of Delhi and the Supreme Court of India. This article is for general information; it is not legal advice and does not create an advocate-client relationship.
Frequently Asked Questions
Who can seek additional evidence in a criminal appeal?
Either side — the appellant-convict, the State, or a complainant-appellant — and the court may also act on its own motion, since the power in Section 433 belongs to the court and is framed by the necessity of the evidence rather than the identity of the mover. Applications are made in the pending appeal, supported by an affidavit explaining what the evidence is and why it was not led at trial.
What is the governing test?
Necessity: the appellate court must think additional evidence "to be necessary" — necessary for a just decision of the appeal, not merely useful or desirable. The reasons must be recorded. Courts guard against two abuses: filling gaps the prosecution left at trial, and manufactured evidence surfacing after conviction. Genuine non-availability, subsequent events bearing on guilt or sentence, and formal proof of documents overlooked below are the typical successful grounds.
Who records the evidence if the application is allowed?
The appellate court may take the evidence itself or direct it to be taken by a Magistrate or, where the appellate court is a High Court, by a Court of Session or a Magistrate. When the evidence is taken below, the certified record is transmitted to the appellate court, and the appeal is then decided on the combined record. The accused or his advocate has the right to be present when the evidence is taken.
Is the appeal decided afresh after additional evidence?
The appeal continues — it is not converted into a retrial. The new material is weighed with the trial record, both sides are heard on it, and the court may confirm, alter or reverse the result, or in appropriate cases order retrial where the defect infects the trial as a whole. Additional evidence is an instrument of appellate justice, not a substitute for the trial process.