Tunnel vision has been defined as “the single minded and overly narrow focus on an investigation or prosecutorial theory so as to unreasonably colour the evaluation of information received and one’s conduct in response to the information.”[114] Tunnel vision, and its perverse by-product “noble cause corruption,”[115] are the antithesis of the proper roles of the police and Crown Attorney. Yet tunnel vision has been identified as a leading cause of wrongful convictions in Canada and elsewhere.

The role of the Crown Attorney has received considerable judicial comment, with frequent emphasis upon the inherent fairness that is integral to the role. The most oft-quoted comment is from Boucher v. The Queen, where Rand J. said:[116]

It cannot be over-emphasized that the purpose of a criminal prosecution is not to obtain a conviction, it is to lay before a jury what the Crown considers to be credible evidence relevant to what is alleged to be a crime. Counsel have a duty to see that all available legal proof of the facts is represented: it should be done firmly and pressed to its legitimate strength but it must also be done fairly. The role of the prosecutor excludes any notion of winning or losing; his function is a matter of public duty than which in civil life there can be none charged with greater personal responsibility. It is to be efficiently performed with an ingrained sense of the dignity, the seriousness and the justness of judicial proceedings.

Crown Attorneys have enormous discretionary power, and the exercise of this discretion must be characterized by fairness and impartiality. The conduct of Crown Attorneys must be consistent with that expected of an Attorney General. Respect for the differing roles of all parties in the criminal justice system should be a hallmark of the Crown Attorney. Casting aside any perceived goal of “winning,” the role of the Crown Attorney is quasi-judicial in nature. As stated in Regan v. The Queen (2002), 161 C.C.C. (3d) 97, “…objectivity and fairness is an ongoing responsibility of the Crown, at every stage of the process.” The Crown Attorney, however, is still expected to be a strong and fearless advocate and hence assertive in putting forward the case. This dichotomy requires a careful balance between advocacy and objectivity. The prosecutor may adopt an adversarial role in the trial process, but the prosecutor should not be a zealot. Within the context of tunnel vision, the Crown Attorney must constantly strive to independently assess the police investigation and the evidence against an accused.

Specific factors that may contribute to Crown tunnel vision, and thus impair the proper role of the Crown Attorney, include:

  1. close identification with police and/or victim;
  2. pressure by the media and/or special interest groups; and
  3. isolation from other perspectives.[117]

Tunnel vision must be guarded against vigilantly, as it is a trap that can capture even the best police officer or prosecutor.


All three Canadian inquiries into wrongful convictions have commented on the perils of tunnel vision, and have made recommendations for police and Crown education on the topic. The Marshall Inquiry emphasized the need for a separation between police and Crown functions. The Sophonow Inquiry recommended regular, mandatory training for police officers on tunnel vision. The Morin Inquiry extended this recommendation to include Crown Attorneys.

a) The Royal Commission into the Donald Marshall, Jr., Prosecution

The Marshall Inquiry stated that "in addition to being accountable to the Attorney General for the performance of their duties, Crown prosecutors are accountable to the courts and the public. In that sense, the Crown prosecutor occupies what has sometimes been characterized as a quasi-judicial office, a unique position in our Anglo-Canadian legal tradition" (pp. 227-28). The Marshall Inquiry emphasized that this role must remain distinct from (while still cooperative with) that of the police (at p. 232):

We recognize that cooperative and effective consultation between the police and the Crown is also essential to the proper administration of justice. But under our system, the policing function -- that of investigation and law enforcement -- is distinct from the prosecuting function. We believe the maintenance of a distinct line between these two functions is essential to the proper administration of justice.

b) The Inquiry Regarding Thomas Sophonow

Tunnel vision

c) The Commission on Proceedings Involving Guy Paul Morin

Recommendation 74 - Education respecting tunnel vision

One component of educational programming for police and Crown counsel should be the identification and avoidance of tunnel vision. In this context, tunnel vision means the 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.

Recommendation 92 - Structure of police investigation

Investigating officers should not attain an elevated standing in an investigation through acquiring or pursuing the “best” suspect or lead. This promotes competition between investigative teams for the best lead, results in tunnel vision and isolates teams of officers from each other.


In his paper, Bruce MacFarlane Q.C. noted that public outrage in high profile cases can translate into intense pressure on the police to arrest and on prosecutors to convict, with speed becoming the overriding factor. He explained how this can contribute to tunnel vision, at p. 40:

Tunnel vision sometimes sets in. The investigative team focuses prematurely, resulting in the arrest and prosecution of a suspect against whom there is some evidence, while other leads and potential lines of investigation go unexplored. It is now clear that that is precisely what occurred in the cases of Morin and Sophonow.

MacFarlane emphasized that raising awareness of the existence of tunnel vision is critical. He recommended that seminars for police and prosecutors should be held, allowing for frank discussion of tunnel vision and stated that police should continue to pursue all reasonable lines of enquiry even where a viable suspect has been identified.


Current Educational Efforts

Crown Initiatives

Crown policies on the role of the Crown have been issued in a number of provinces.


While the provision of lectures on the topic of tunnel vision are important, they are not the sole answer to its prevention. The best protection against tunnel vision is a constant and acute awareness of the role of the Crown Attorney, and the relationship of the Crown and police to each other and to other participants in the justice system.

The separation of police and Crown roles is a well-established principle of our criminal justice system. This separation has led to cultural differences that should be recognized by both groups. Mutual independence of Crowns and police is key to the prevention of tunnel vision, as it creates a system of institutional checks and balances. It is important to recognize, however, that different provinces have implemented this principle in various ways, and that varying nuances and complexities exist in the relationships between Crowns and police in different jurisdictions.

For instance, generally the role of the Crown at the pre-charge stage is advisory in nature, and not directive. In some jurisdictions, however, police require pre-charge approval from the Crown. Even in jurisdictions where Crown pre-charge approval is not required, there may, by necessity, be Crown involvement prior to the charge being laid. One example would be a case involving wiretaps. In Regan v. The Queen (2002), 161 C.C.C. (3d) 97, the Supreme Court of Canada accepted the necessity of pre-charge involvement in certain circumstances. The Court concluded that objectivity is not necessarily compromised by pre-charge involvement. However, a distinction should be drawn between pre-charge advice and advising the police on the grounds to lay a charge. It is in this latter situation that the spectre of tunnel vision usually arises.

With the possible exception of mega-cases,[118] it is recommended that all jurisdictions consider adopting a “best practice” of having a different Crown Attorney prosecute the case than the Crown Attorney who provided the charging advice. This recommendation, however, must take into account the realities of some prosecution services, where there may be a single prosecutor for a large geographic area. In some communities there may be only one Crown Attorney who handles many “routine” matters and is the sole contact with the local police. This can lead to close identification between the Crown and police, and hence a reluctance to disagree. In such situations, second opinions and supervision by senior/regional Crown counsel should always be available. There should be clear identification of the roles and accountabilities within the prosecution service, including the hierarchy of responsibility. In jurisdictions without pre-charge screening, it is further recommended that there be a speedy review of the charge so as to identify any problems at an early stage.

Consultations or case reviews may occur before, during, or after a prosecution. While these consultations may not be appropriate for every case, or even for every serious case, they can be used in situations where counsel are facing difficult, unique or unusual circumstances. Counsel with carriage of the case should be encouraged to review the case with other senior counsel to discuss legal, practical and advocacy strategies. Often cases require a method of problem solving and this case consultation mechanism can be used either as a preventative measure while the case is ongoing, or as a lessons learned session after the case is over. This consultation process is used by other professional groups, such as doctors, and is recognized as an effective tool.

After a charge is laid, the Crown has independent control over the charge and has the sole authority to proceed with the prosecution or withdraw the charge. Early consultation between prosecutors and police should be encouraged. It is important that police training emphasize this separate function of the Crown, so that in appropriate cases, the Crown Attorney may feel unhindered in deciding not to proceed any further with a charge. It is easy to envision situations where fear of criticism or unfavourable comparisons with other prosecutors could hamper the Crown Attorney from discharging his or her duties. This emphasis upon the separate function of Crowns and police also encourages Crowns to be open to theories that may be different from those initially put forward by the investigator. Crown counsel must always act as a challenge function to police officers and must bring critical eyes to bear on the evidence presented to them. They must always be prepared to consider alternate theories and explanations for such things as post-arrest conduct. While prosecutors and police officers must work together closely and co-operatively, the different responsibilities and the different standards they must apply should not be impaired.

A Crown Attorney must also be wary of decisions being influenced by media coverage or by negative responses by victims. The role of the Crown is often misunderstood by victims and the general public. The Crown Attorney’s role as a quasi-judicial officer includes a duty to both the accused and the Court. It is therefore incumbent upon the Crown to foster respect for both the Court and the rights of the accused. Even when the role of the Crown is understood, decisions based upon sound legal analysis may be unpopular. It is therefore important that the workplace culture of prosecutors emphasize the role of the Crown Attorney, and that there be policies in place that support that role. Prosecutors must be wary of being caught up in the enthusiasm of the investigators. Workplace environments should encourage questions and consultations between individual Crown Attorneys. An openness to alternate views, including those held by defence counsel, is reflective of the independence of the Crown Attorney.


The following practices should be considered to assist in deterring tunnel vision:

  1. Crown policies on the role of the Crown should emphasize the quasi-judicial role of the prosecution and the danger of adopting the views and/or enthusiasm of others. Policies should also stress that Crowns should remain open to alternate theories put forward by defence counsel and other parties.
  2. All jurisdictions should consider adopting a “best practice,” where feasible given geographic realities, of having a different Crown Attorney prosecute the case than the Crown Attorney who advised that there were grounds to lay the charge. Different considerations might apply with mega-cases.
  3. In jurisdictions without pre-charge screening, charges should be scrutinized by Crowns as soon as practicable.
  4. Second opinions and case review should be available in all areas.
  5. There should be internal checks and balances through supervision by senior staff in all areas with roles and accountabilities clearly defined and a lead Crown on a particular case clearly identified.
  6. Crown offices should encourage a workplace culture that does not discourage questions, consultations, and consideration of a defence perspective by Crown Attorneys.
  7. Crowns and police should respect their mutual independence, while fostering cooperation and early consultation to ensure their common goal of achieving justice.
  8. Regular training for Crowns and police on the dangers and prevention of tunnel vision should be implemented. Training for Crown Attorneys should include a component dealing with the role of the police, and training for police should include a component dealing with the role of the Crown.

Critical to the success of any of these recommendations is the provision of resources to allow Crown Attorneys and police to fulfill their roles. Financial, as well as non-financial resources, will be necessary to encourage changes in organizational attitudes, practices and culture.

Above all it must be remembered that tunnel vision is not unique to a particular situation, province or indeed country.[119] As stated by Justice Cory in the Sophonow Inquiry, “tunnel vision is insidious.”[120] It can thrive in any environment and thus there must be constant vigilance.