Observations on the Rehabilitation of a Witness

As part of my Master of International Law studies, I have been reflecting on how evidence law balances two competing concerns: the need to test a witness’s credibility and the need to ensure fairness when that credibility comes under attack. One particularly interesting area is the rehabilitation of a witness — the rules that allow a party to restore credibility after it has been challenged.

The Common Law Approach

At common law, the general rule is clear: a party cannot pre-emptively bolster its own witness’s credibility. It is only once credibility has been attacked — usually in cross-examination — that rehabilitation becomes permissible. The rationale is practical: trials would be needlessly lengthened if every witness was accompanied by “character evidence” before any challenge had been made.

Observations on the Rehabilitation of a Witness

That said, when an allegation of misconduct or inconsistency arises, the rules allow significant flexibility. A witness may deny the allegation in re-examination, and the scope of re-examination is deliberately broad so that they may explain damaging answers or provide context. In some cases, the witness may even be recalled if the attack occurred through another witness.

Where credit has been impeached through evidence of lack of veracity, rebuttal evidence can be called to affirm credibility. The case law reveals some uncertainty over how far rebuttal can go, particularly where the attack falls short of alleging a crime. Yet, as Wigmore noted, efficiency and finality remain important considerations — the court’s discretion remains central.

Explaining Apparent Inconsistencies

Another fascinating dimension is the use of explanatory evidence to resolve conduct that seems inconsistent with testimony. For example, psychological or expert evidence may sometimes be admitted to explain why a witness’s behaviour did not necessarily undermine their truthfulness. This is carefully confined: the evidence must not simply tell a jury that the witness is honest, but may help contextualise behaviour that might otherwise look suspicious. Courts remain cautious here, wary of turning trials into battles of experts rather than matters for juries.

The Statutory Framework

Modern statutes, including the Evidence Acts 1995 (Cth and NSW), 2008 (Vic), 2001 (Tas), and 2011 (ACT and NT), now make specific provision for rehabilitation. Section 108 allows:

• Evidence in re-examination without being excluded by the credibility rule; and

• Admission of prior consistent statements where credibility has been attacked by proof of inconsistency, or where it is suggested that the testimony has been fabricated, reconstructed, or is the result of improper suggestion — but only with the court’s leave.

These provisions broadly mirror the common law but provide greater clarity and consistency across jurisdictions.

My Reflections

For me, the rehabilitation of a witness illustrates how the law of evidence seeks equilibrium.

On one hand, credibility must be rigorously tested; on the other, witnesses deserve a fair chance to answer attacks. It is striking that the law does not give an automatic licence to flood the court with supporting material — instead, it relies on judicial discretion to ensure proportionality.

From a comparative international perspective, the principle resonates with broader procedural fairness doctrines. Whether in common law courts, civil law systems, or international tribunals, credibility challenges must be balanced by the opportunity for rebuttal and explanation. Without such balance, justice risks being undermined by untested insinuation.

In my view, rehabilitation rules are not just technicalities. They embody a deeper commitment to fairness: that while the adversarial system allows sharp attacks on credibility, it also ensures a witness is not left defenceless in the face of challenge.