The Duty to Disclose: Why Stinchcombe Still Defines Fair Trials in Canada

By Janie A. Duncan, President of Duncan Investigations Inc.

In Canadian criminal law, few cases have had the lasting impact of R. v. Stinchcombe. For legal professionals, investigators, and anyone concerned with justice, this decision is more than just precedent—it is a safeguard against wrongful convictions and a cornerstone of fairness. At Duncan Investigations Inc., we see firsthand how disclosure, or the lack of it, can significantly influence the outcome of a case.

The Supreme Court of Canada made it clear in Stinchcombe that the Crown has a duty to disclose all relevant information to the defence. This obligation is not optional and is firmly rooted in the accused right to make full answer and defence under section 7 of the Canadian Charter of Rights and Freedoms. This means that the Crown must disclose all relevant evidence, whether it strengthens or weakens its case, and regardless of whether the Crown intends to rely on it at trial. The crown's purpose is not to secure a conviction, but to ensure that justice is done.

The facts of Stinchcombe illustrate the consequences of failing to meet this obligation. The case involved a lawyer charged with fraud and breach of trust. A key witness had previously provided evidence that appeared favourable to the defence. However, after further police interviews, new statements were obtained from that witness. The Crown ultimately chose not to call the witness and refused to disclose the contents of those statements. As a result, the defence was denied access to potentially critical information that could have influenced its strategy. The Supreme Court found this to be a serious breach of the Crown’s duty and ordered a new trial.

One of the most important outcomes of Stinchcombe was the rejection of “trial by ambush.” Prior to this decision, there was often an element of surprise in criminal proceedings. The Court firmly moved away from that approach, emphasizing that the fruits of an investigation are not the property of the Crown to secure a conviction, but to ensure the right to a fair trial. This shift fundamentally changed how prosecutions are conducted in Canada, placing fairness and transparency at the forefront.

While the duty to disclose is broad, it is not absolute. There are limited circumstances where disclosure may be restricted, such as cases involving informer privilege, concerns for witness safety, or information that is clearly irrelevant. However, these exceptions are narrow and carefully scrutinized. If there is a reasonable possibility that the information could assist the defence, it should be disclosed. Moreover, any decision to withhold information is subject to review by the court.

In practice, despite the clarity of the law, issues surrounding disclosure still arise. We regularly encounter situations where witnesses are not fully pursued, statements are incomplete or inconsistent, or relevant individuals are overlooked entirely. Disclosure is only as comprehensive as the investigation behind it. If something is not uncovered, documented, or recognized as relevant, it may never form part of the disclosure process.

This is where private investigators play a critical role. At Duncan Investigations Inc., we are often engaged to provide an independent and thorough review of the facts. However, the Stinchombe case applies directly to criminal matters and those that have been accused of serious criminal offenses. Our investigations have played a critical role in cases where key information has been overlooked or not properly disclosed. Through our work, we have uncovered instances where the Crown or police failed to fully disclose all relevant evidence, or did not pursue crucial witness interviews that may have significantly altered the direction of a case. This is why it is so important to be very through in all investigations, to ensure that it is a fair and balanced investigation and to assess the credibility of all witnesses.

Canada has seen the consequences of failures in disclosure and incomplete investigations. The findings of the Inquiry into the wrongful conviction of James Driskell have demonstrated how non-disclosure contributed to a wrongful conviction. That case serves as a powerful reminder that justice depends not only on the existence of rules like Stinchcombe, but on their proper application in practice.

Ultimately, R. v. Stinchcombe stands for a simple but essential principle: justice requires transparency. For defence counsel, it is a vital tool in protecting the rights of the accused. For the Crown, it is a constitutional obligation that must be taken seriously. For investigators, it is a reminder that every piece of information matters and that the truth often lies beyond what is initially presented.

At Duncan Investigations Inc., we understand that behind every case is a real outcome—one that can be shaped by what is found, what is disclosed, and what is left unseen.