Evidence

Evidence law is the body of law that governs how facts are proved in legal proceedings. In the Australian Capital Territory (ACT), the law of evidence is primarily governed by the Evidence Act 2011 (ACT), which forms part of the Uniform Evidence Law framework used across most Australian jurisdictions.

In criminal proceedings, evidence law determines:

• What evidence can be admitted or excluded in court
• how evidence must be collected and preserved
• How witnesses may be examined and challenged
• the fairness and reliability of the trial process

The overarching purpose is to ensure that criminal trials are fair, reliable, and based on properly tested material.

Collection and Handling of Evidence

In criminal law, evidence rules extend beyond the courtroom and regulate how law enforcement gathers and manages material used in prosecutions. This includes:

• police interviewing suspects and accused persons
• conducting searches and seizures under warrant or lawful authority
• handling and preserving forensic evidence (such as DNA, fingerprints, and digital data)
• maintaining continuity of evidence (chain of custody) to prevent contamination or tampering

If evidence is improperly obtained, it may later be excluded by the court.

Admissibility of Evidence in Court

Not all information can be used in a criminal trial. The Evidence Act 2011 (ACT) sets out strict rules governing admissibility.

To be admitted, evidence must generally be:

• relevant to a fact in issue
• not excluded by a specific rule of evidence
• not unfairly prejudicial or improperly obtained

Key Categories of Evidence Rules

Evidence law regulates several important categories, including:

• Hearsay evidence – statements made outside court offered to prove the truth of their contents
• Opinion evidence – generally restricted unless given by an expert or in permitted circumstances
• Relevance – only evidence that assists in proving or disproving a fact in issue is allowed
• Privilege – certain communications (such as legal professional privilege) are protected
• Identification evidence – rules governing eyewitness identification and related risks of misidentification

Witness Examination

Witnesses play a central role in criminal proceedings. Evidence law governs how they are questioned, including:

• Examination-in-chief – questioning by the party calling the witness
• Cross-examination – questioning by the opposing party to test reliability and credibility
• Re-examination – follow-up questioning to clarify issues raised in cross-examination

The law also determines who is:

• competent to give evidence (able to understand and communicate evidence)
• compellable (legally required to testify, subject to certain exceptions)

Voir Dire (Preliminary Hearings on Evidence)

When there is a dispute about whether evidence should be admitted, the court may conduct a voir dire (a preliminary hearing).

During a voir dire:

• the judge determines whether evidence is admissible
• arguments may be heard about how evidence was obtained
• evidence may be ruled as either excluded or allowed before the main trial continues

While some evidence is clearly admissible or inadmissible, many situations require judicial discretion and careful legal assessment.

Exclusion of Evidence

Even if evidence is technically admissible, courts may still exclude it in certain circumstances.

Under the Evidence Act 2011 (ACT), courts may exclude evidence where:

• its probative value is outweighed by unfair prejudice
• it was improperly or illegally obtained (often considered under s 138)
• it would be unfair to the accused to admit it

This discretionary power ensures that the integrity of the justice system is maintained, and that trials remain fair.

Purpose of Evidence Law in Criminal Proceedings

Overall, evidence law in the ACT aims to balance two key principles:

• Truth-seeking – ensuring reliable and relevant evidence is presented
• Fairness – protecting accused persons from unreliable, prejudicial, or improperly obtained evidence

By regulating how facts are proved, evidence law plays a critical role in maintaining justice in criminal trials.