Tunnel vision is a significant problem under the umbrella of professional misconduct. In the Morin Inquiry, tunnel vision was defined 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.” In some cases, police and prosecutors seek evidence that fits their theory as opposed to developing a theory based on existing evidence.
Police and prosecutors affected by tunnel vision don’t necessarily have bad intentions. They also don’t necessarily realize they are suffering from its sinister effects. Pressure to solve a crime and ensure the perpetrator is ‘brought to justice’ increases this psychological phenomenon.
To reduce the potential for tunnel vision, all actors in the criminal justice system should remain objective and avoid making any conclusions too early on. They can also share observations and ask for advice from colleagues to get an outsider’s perspective.