Chapter 4 – Tunnel Vision


I. Introduction

Tunnel vision distorts the perception of evidence. It is one of the contributors to wrongful convictions and is seldom caused by malice. It is “insidious”Footnote 78 and may infect police, prosecutors, and judges.

Tunnel vision has been described 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 the information.”Footnote 79 When evidence is incorrectly “filtered” a biased approach develops.Footnote 80 Quite often this is “reinforced” as police and prosecutors assigned to a case interact without critically assessing the evidence or testing the investigative theory.Footnote 81 The results can be devastating.

A wrongful conviction forces the justice system to seek answers. The tunnel vision “malaise”Footnote 82 infects police and prosecutors in different places, and at different times. Institutional pressure on the police to solve the crime and various pressures on prosecutors to win those cases can lead to flawed conclusions.Footnote 83 The prosecutor’s role must be well understood by the community and the justice system participants, including, most importantly, the prosecutor.

A prosecutor must never over-reach to obtain a conviction. Evidence gathered by the police must be scrupulously evaluated and assessed to confirm it meets evidentiary rules for admissibility. The prosecutor’s quasi-judicial function “excludes any notion of winning and losing.”Footnote 84 Prosecutors must be fair. They must have courage, exercise contrarian thinking, and be able to make unpopular decisions.Footnote 85 Prosecutors “may have to poke and prod the investigators to ensure that they were not afflicted by tunnel vision. Hard questions must be asked and firm measures taken to ensure the integrity of the administration of justice.”Footnote 86

Tunnel vision and noble cause corruption are closely related. Once the police are convinced they have identified the perpetrator then dubious investigative practices may be utilized to achieve their ends.Footnote 87

Prosecutors, too, may be susceptible to the same systemic factors which can result in tunnel vision such as: public pressure, a weak circumstantial case, relying on questionable evidence, maligning a suspect who is a societal outcast or a member of a minority, close association with the investigative police team, and the improper use of prosecutorial practices to achieve the desired outcome.Footnote 88

II. 2005 Recommendations

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.

III. Canadian Commissions of Inquiry Since 2005

a) The Lamer Commission of Inquiry Pertaining to the Cases of: Ronald Dalton, Gregory Parsons, Randy Druken (2006)

A. Gregory Parsons

Less than 24 hours after Catherine Carroll’s body was discovered, the main investigator had concluded that Gregory Parsons had murdered his mother. Commissioner Lamer found “the investigators were securely ensconced in the tunnel.”Footnote 89 There was no critical analysis of the evidence. The hearsay statements of the victim, despite the internal inconsistencies and complexity of the maker, were accepted as reliable. Key witnesses were poorly interviewed, with the police taking no, or few, notes. The police used heavy-handed tactics to influence witnesses to give evidence favouring the police theory.Footnote 90 The police regarded Mr. Parsons’ demeanour as “suspicious.” Commissioner Lamer commented that “to interpret meaningless ‘demeanour’ as proof of guilt is, rather, proof of tunnel vision.”Footnote 91 He also identified “a common feature of tunnel vision” which “is to treat innocuous evidence as incriminating and to exaggerate the significance of marginally suspicious evidence.”Footnote 92 Contradictory evidence and important evidence were ignored.

Commissioner Lamer recommended the Royal Newfoundland Constabulary consider incorporating into its policies the recommendations of the Morin Inquiry regarding “note-taking, interviewing and statement-taking.” Developing police standards for qualifications, “initial and ongoing training and criminal investigation” were encouraged.Footnote 93

Crown counsel, who was to provide legal advice to assist the investigators, may have been too close to the investigation and did not perform the “challenge function.” Crown counsel at trial also had this responsibility.

Commissioner Lamer found “… the DPP’s office demonstrated a Crown culture that accepted and supported the police tunnel vision.”Footnote 94

He recommended, among other things, establishing a “failsafe system” for critical assessment of files, encouraging mentoring by experienced prosecutors with those who are junior, providing clear guidelines to avoid tendering inherently unreliable evidence, and developing and maintaining a “Crown culture that is sensitive to the opportunities to avoid injustice as well as to obtain convictions.”Footnote 95

B. Randy Druken

Brenda Young was murdered in 1993. The police investigation occurred about 2½ years after the investigation into the murder of Catherine Carroll. The lead investigator concluded a short time after the murder that Randy Druken was responsible. There was no critical assessment of the case by the police or the prosecutor. Key witnesses were approached by the police to either change or bolster their statements. This was a “clear reflection of tunnel vision.”Footnote 96 Tunnel vision drove the investigation and led to mistakes in conducting the polygraph and in using the results. The police and prosecutor shared the view that the murder occurred in the kitchen, the body was moved into the living room and that a clean-up occurred. There was no forensic evidence to support this theory. The child witness had been manipulated by adults. Her story changed with subsequent interviews. She eventually implicated Mr. Druken. The Commissioner commented that “the vulnerability of children is increased when tunnel vision is at play…”Footnote 97 He found the police had no oblique motive but were driven by systemic forces. Tunnel vision was also exhibited by the prosecutor who led the evidence of the jailhouse informant, Mr. X, despite knowing that Mr. X had failed a polygraph test. Crown culture was responsible for accepting and advocating the police tunnel vision. This continued when a stay of proceedings was filed and then expired. The Crown was criticized for seeking “to prolong that tunnel vision.”Footnote 98

Commissioner Lamer recommended a new policy for prosecutors on the termination of proceedings and that the recommendations with respect to jailhouse informants contained in the Sophonow Inquiry Report be incorporated into the Crown Policy Manual.

b) Inquiry into Pediatric Forensic Pathology in Ontario (2008)

Commissioner Goudge discussed the danger of “confirmation bias” as a result of pre-autopsy communications between the police and forensic pathologist. He said police officers must be equally vigilant against confirmation bias in their own investigative work and even in casual unguarded conversations must objectively present the evidence.

Specifically, he recommended:

Recommendation 75

The forensic pathologist should remain vigilant against confirmation bias or being affected by extraneous considerations. This is best done through increased professionalism and education, an enhanced awareness of the risks of confirmation bias, the promotion of an evidence-based culture, complete transparency concerning both what is communicated and what parts of it are relied upon by the pathologist, and a cautious approach by the pathologist to the use of circumstantial or non-pathology information.Footnote 99

Recommendation 110

The police should be trained to be vigilant against confirmation bias in their investigative work generally, and for pediatric forensic cases in particular. This training is best accomplished through increased professionalism, an enhanced awareness of the risks of confirmation bias, the promotion of an evidence-based culture, and complete transparency regarding what is communicated between the police and the forensic pathologist.Footnote 100

IV. Legal Developments and Commentary

Robert J. Frater, in his article “The Seven Deadly Prosecutorial Sins,” opines of prosecutorial autonomy that “despite the fact that the independence principle remains significant, it has probably been eclipsed in importance at this moment in time by a principle of accountability.”Footnote 101 Prosecutors are responsible for the decisions they make and may be required to articulate the reasons for these decisions. They are accountable, ultimately, to the public. This introspective look is necessary and desirable. A Crown culture which focuses on winning runs the risk of losing sight of its public responsibility, and will inevitably fall into tunnel vision.

Tunnel vision is the antithesis of an open mind. It causes prosecutors to overreach to save a weak case. But tunnel vision may also be present post-conviction. In “Crown Culture and Wrongful Convictions: A Beginning,” Melvyn Green, a former president of the Association in Defence of the Wrongly Convicted and now a judge of the Ontario Court of Justice, concludes that the Crown’s power to stay proceedings and its resistance to admitting mistakes may demonstrate tunnel vision.Footnote 102 He recommends that police and prosecutors admit errors and take such measures to “identify and inoculate themselves against the risk of error” and endorses implementing regular training for prosecutors and police on identifying and eliminating tunnel vision.Footnote 103

“The Multiple Dimensions of Tunnel Vision in Criminal Cases” is one of the most significant papers on this subject.Footnote 104 Although the case studies discussed are from the United States, they highlight the universal feature of this legal malady. The paper identifies cognitive biases and institutional pressures as the sources of tunnel vision and discusses numerous ways to correct its effects. Professors Findley and Scott identify the psychological phenomenon of cognitive biases: confirmation bias, hindsight bias, and outcome bias. These biases occur naturally in our everyday living when we seek to affirm what we already thought was the case (confirmation bias), look into the past with the belief that we “knew it all along” (hindsight bias), or apply future knowledge into the past to evaluate the quality of a decision (outcome bias). While acknowledging that tunnel vision is “to an extent inevitable” it must be guarded against.

But the innateness of these cognitive biases and distortions does not absolve actors in the criminal justice system from responsibility to try to overcome tunnel vision; to the contrary, it demands that we become aware of these cognitive processes and the tunnel vision they produce, and that we search for ways to neutralize them. Unfortunately, the criminal justice system fails to do that. Rather both institutional pressures inherent in the adversary system and explicit policy choices reinforce and exacerbate the natural tendencies toward tunnel vision.Footnote 105

The adversary system creates institutional pressure “to win” and contributes to tunnel vision. Police face public pressure to solve crimes quickly, an unrealistic expectation that crimes will be solved, sheer volume of cases, and performance evaluations based on minimal standards such as reasonable and probable grounds.Footnote 106 Prosecutors, too, can succumb to the desire to obtain a conviction. They may be isolated from the entire investigative file and not see alternate police theories which were discounted too quickly. Prosecutors may also think they are serving the interests of justice.Footnote 107

Systemic choices can enforce tunnel vision. The Reid police interrogation technique used by many forces is premised on the police theory that the suspect can be broken down and will consequently confess. Evidentiary rules employed at trial may prevent the admission of exculpatory evidence. The appellate process may also place limitations on the ability of the wrongfully convicted to seek redress.Footnote 108

Professors Findley and Scott recommended considering doctrinal reforms to ensure legal rules allow evidence relevant to innocence.Footnote 109 Education and training for police and prosecutors “to place greater value on neutrality, emphasizing the need to postpone judgment and to develop all the facts rather than merely building a case against a suspect.”Footnote 110 Judges as well as police and prosecutors should be informed about the dangers of tunnel vision.Footnote 111 Improved procedures for collecting physical and testimonial evidence were also suggested.Footnote 112 Other recommendations included the factors to be considered in selecting the investigative team, with emphasis on the crucial role of the investigative supervisor, ensuring the prosecutors have access to the entire case materials, employing multiple levels of case review, greater transparency, more independence between the forensic labs and the police and prosecution services, and external review panels.Footnote 113

Bruce MacFarlane, in his paper entitled “Wrongful Convictions: The Effect of Tunnel Vision and Predisposing Circumstances in the Criminal Justice System,” identifies tunnel vision as one of the two critical factors leading to wrongful convictions. He found noble cause corruption and tunnel vision to be closely linked. Once investigators think the suspect is the perpetrator, they may use questionable methods to achieve their goals.Footnote 114 They become willfully blind at an institutional or personal level, or both.Footnote 115 Societal demands, resource constraints, emotional attachments, and the strength of the victims’ rights movement, all contribute to institutional pressure on the police.Footnote 116 Similarly, prosecutors face the pressure to convict, think they must “believe in their case,” are given only the evidence implicating the accused, and forge close ties with the police.Footnote 117 The importance of keeping an open mind and an institutionalized model for contrarian thinking for police, prosecutors, and forensic pathology are recommended in this review.Footnote 118

Early stage investigative review was advocated by Professor Christopher Sherrin in his Comment on the 2005 Report.Footnote 119 In complex cases, before the decision has been made to focus on a particular suspect, he recommends an independent person review the material gathered by the police. He suggests that this person could be a prosecutor or even someone with investigatory experience who works within the police agency but is detached from the investigation.Footnote 120

Canadian courts have also commented on confirmation bias or tunnel vision. The Manitoba Court of AppealFootnote 121 discussed the approach taken by Commissioner Goudge which promotes objectivity in pediatric forensic pathology. The appellant had argued that the forensic pathologist was “thinking dirty,” thus demonstrating confirmation bias and presuming abuse. The Court, however, rejected this argument and found that the forensic evidence and the autopsy report had considered the possibilities which had been raised by counsel and were transparent in their findings. In the Supreme Court of Canada, Mr. Justice Binnie has expressed his concern over the “growing platoon of the wrongfully convicted” which stems from police tunnel vision and flawed investigations.Footnote 122

V. Status of Recommendations

Across the country, all prosecution services have policies which clearly articulate the role of the Crown and the importance of on-going critical assessment of cases to prevent tunnel vision.

For example, Newfoundland and Labrador prosecutors have a new policy manual which incorporates the recommendations of the Lamer Inquiry Report. This Guide Book of Policies and Procedures for the Conduct of Criminal Prosecutions in Newfoundland and Labrador devotes an entire chapter to the “Duties and Responsibilities of Crown Attorneys.” It reminds prosecutors that they have a duty to be fair “by carefully guarding against the possibility of being afflicted by ‘tunnel vision’ and of practicing ‘overzealousness’ or ‘overreaching advocacy’ through close identification with the investigative agency and/or victim, or through pressure by the media and/or special interest groups or to ‘shore up’ a weak case.”Footnote 123 Critical assessment of charges, the role of the prosecutor, and the relationship between the police and the prosecutor are emphasized. A stay of proceedings is never permitted to expire without the prosecutor taking action to either terminate the proceedings or to continue with the prosecution.

The policy manual for the Public Prosecution Service of Canada, known as the Deskbook, was revised after the release of the 2005 Report in keeping with the Report’s recommendations. Several Deskbook chapters now include specific guidance to federal prosecutors aimed at the prevention of wrongful convictions. For example, in the chapter concerning The Duties and Responsibilities of Crown Counsel,Footnote 124 federal prosecutors are reminded to remain attuned to the factors that can lead to wrongful convictions, such as false confessions and mistaken eyewitness identification. The chapter also advises prosecutors that tunnel vision has been identified as a leading cause of wrongful convictions and warns prosecutors to zealously guard against the possibility of being afflicted by it through close identification with the investigative agency and/or victim, or through pressure from the media and/or special interest groups. Federal prosecutors are also advised to remain open to alternative theories of the case advanced by the defence. Similar advice is included in other chapters, such as the chapters concerning The Relationship between Crown Counsel and the Police,Footnote 125 and The Decision to Prosecute.Footnote 126 For example, the former chapter warns Crown Counsel that, in assessing the strength of the case at the end of the police investigation, they must guard against the possibility that they have fallen victim to tunnel vision and, for example, have lost the ability to conduct an objective assessment of the case through contact with the investigative agency.

The new PPSC Deskbook will include a separate chapter concerning the Prevention of Wrongful Convictions.

In British Columbia, Crown Counsel have the responsibility to make a charge assessment decision which determines whether or not a prosecution will proceed. The charge assessment standard continues to apply throughout the prosecution.

Prosecutors in Quebec follow a specific directive which requires them to keep an open mind after they have been granted the authority to proceed with a prosecution. They must re-evaluate all new facts to determine whether there is sufficient evidence to continue with the prosecution.

Alberta’s Policy The Decision to Prosecute Policy reminds prosecutors that consultation is critical:

Consultation, including the seeking out of second opinions and discussions regarding legal, practical and advocacy strategies, can be an important aspect of prosecutorial decision-making. Such consultation can, for example, help Crown prosecutors avoid succumbing to so-called tunnel vision. While consultation may not be necessary or appropriate for every case, or even for every serious case, the responsible exercise of prosecutorial discretion, including deciding whether to prosecute, often requires consultation with colleagues uninvolved in the prosecution of the case, with superiors and/or with investigators. Indeed, in cases involving the most serious of offences -- particularly homicides -- and those involving novel arguments or unusual circumstances, consultation with colleagues uninvolved in the prosecution of the case may be critical to the decision to proceed (or not) with the prosecution. In respect of such cases, this consultation ought to take place early on in the process, but no later than on completion of a preliminary inquiry.

Most Canadian police forces now use the Major Case Management (MCM) methodology for managing major investigations. The process provides structure, accountability mechanisms, clearly defined goals/objectives, defined procedures, consistency, and efficient use of available resources.

The development of the model has arisen, in part, as a result of many of the miscarriage of justices that have occurred due to failed investigations. Errors in the management, structure and leadership of these cases have contributed to the failures. As a result, MCM has been used in Canadian police forces as a methodology for planning, organizing, structuring and leading major cases to varying degrees. The goal of MCM is to ethically and lawfully conduct complete, competent and high quality investigations which support successful prosecutions.

The role of the Devil’s Advocate or Contrarian is included in the MCM model when the Command Triangle conducts brainstorming sessions and investigational briefings. This “role” can be assigned to any one person or it can be a mindset for the investigative team. The main purpose for this role is to prevent or attempt to prevent tunnel vision from occurring in an investigation by using critical thinking skills.

The Canadian Police College, which provides advanced and specialized professional development, training and education to law enforcement officers from across Canada, offers a Major Case Management-Team Commander training course. It has a full day-long segment on strategic decision making, using critical thinking skills to assist future Team Commanders in recognizing the onset of tunnel vision.

VI. Discussion of Recommendations

Tunnel vision can be treated once it is accepted that it exists. A police or Crown culture which refuses to acknowledge that it can be infected loses sight of its ultimate goal and perpetuates this error. Education sessions which emphasize the role of these two justice system participants lay the foundation for building strong and healthy organizations. Interaction between the police and prosecutors should be carefully understood. Prosecutors must play the challenge function. This can be done in various ways in the pre-and post-charge assessment of the case. The police, during the investigatory phase, must establish a process to ensure that all of the evidence gathered is considered and not discarded prematurely. In major investigations, an experienced and detached police officer and/or a prosecutor could be tasked with sifting through the investigative materials and providing advice and direction to the investigative team to ensure all leads are being pursued. Evidence should be obtained in a manner consistent with the search for the truth. Prosecutors must continuously critically assess the prosecution once the charge has been laid. This responsibility continues where an appeal has been filed.

Understanding that nature predisposes us, through cognitive biases, to be affected by tunnel vision should make us more vigilant. Institutional pressures also make us more susceptible to be trapped within the tunnel. It is imperative that through educational awareness, police and prosecutors understand the nature and causes of tunnel vision so they can take preventative measures to avoid its deleterious effects.

VII. Summary of Recommendations

While the 2005 Report’s recommendations remain valid, the Subcommittee recommends slight refinements as follows:

  1. Crown policies on the role of the Crown should emphasize the quasi-judicial nature of the position and the inherent danger of adopting the viewpoints or enthusiasm of others without thorough analysis. Policies should encourage prosecutors to remain open to alternate theories proffered by defence counsel or other credible parties.
  2. Where geography and resources permit, jurisdictions should consider implementing a best practice whereby a prosecutor who had significant pre-charge involvement is replaced by another prosecutor to maintain carriage of the file post-charge.
  3. In jurisdictions without pre-charge screening, charges should be reviewed by prosecutors as soon as practicable and an ongoing critical assessment must be made.
  4. Second opinions and case reviews should be available in all areas.
  5. Internal organizational accountability should be clearly defined and understood. Prosecutors must understand their role in each prosecution and the respective role of their supervisors.
  6. A Crown culture which encourages discussion and contrarian thinking should be cultivated in Crown Law offices.
  7. Law enforcement agencies and prosecutors play complementary roles in the criminal process. While they both enjoy institutional independence at their respective stage of the process, it does not preclude cooperation and mutual assistance to strive for justice.
  8. Training for prosecutors and police on the prevalence and prevention of tunnel vision should be implemented. Prosecutors and police should have a clear understanding of each other’s role in the criminal justice system.
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