Tunnel Vision

I teach on this topic in one of my Police Foundation classes.

Experts define tunnel vision as a “single-minded and overly narrow focus on a particular investigative or prosecutorial theory, so as to unreasonably colour the evaluation of information received and one’s conduct in response to that information.”

Police officers and Crown counsel affected by tunnel vision can become so convinced that the correct suspect has been identified and that the theory of the case is correct, that they see only the evidence that supports that theory and ignore facts and information that do not support it.

Crown counsel must not only watch for signs of tunnel vision among the police officers involved in the investigation of the case, but they must also constantly guard against developing it themselves. One of the greatest safeguards for Crown counsel is to bear in mind the key principles regarding the role of the Crown so clearly articulated in the classic case of Boucher v The Queen.  In their review of the evidence in a given case, Crown counsel must remain cognizant of their duty to be fair and impartial, and to ensure they review the evidence in an objective, rigorous and thorough manner. Crown counsel fulfil a gatekeeper function by virtue of the Crown’s duty to critically and independently assess the evidence presented by the police.

While Crown counsel should, where appropriate, encourage co-operation and early consultation with the police during police investigations, it is crucial that Crown counsel understand the distinct and independent role of the Crown vis-à-vis the police.

Although the police are responsible for directing the investigation, during the file review, Crown counsel should not hesitate to question aspects and perceived shortcomings of the police investigation that relate to the sufficiency of the evidence and impact the prospect of conviction. A fair, independent and impartial review of the file by Crown counsel also means remaining open to alternative theories of the case, which may be different from the theory advanced by the police. Public Prosecution Service of Canada (PPSC) managers and Crown counsel should also strive to create a workplace atmosphere that encourages questions, consultations and frank discussion and debate among Crown counsel and that is receptive to the expression of alternative views regarding a case.

During file review and trial preparation, checks and balances through supervision and second opinions should be encouraged. Crown counsel with carriage of the file may consider consulting a fellow Crown counsel who can play the role of a contrarian or devil’s advocate. This can be a very useful technique, particularly in the most serious cases. Mentoring should be encouraged regarding various aspects of Crown counsel’s role, such as the importance of the independent role of Crown counsel vis-à-vis the police, and the appropriate limits of Crown advocacy.

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