Confirmation Bias and Other Systemic Causes of Wrongful Convictions: A Sentinel Events Perspective

Abstract

Wrongful convictions are a form of criminal investigative failure. Such failures are sentinel events that signal underlying structural problems within a weak system environment. Similar to transportation or medical accidents, they are often the result of multiple and co-occurring causes. However, unlike the response to an airplane crash, the criminal justice system typically makes little effort to understand what went wrong. These failures tend to be ignored and systemic reviews are rare. As a consequence, important necessary procedural changes and policy improvements may not occur. In this article, we discuss a National Institute of Justice-funded research project that was designed to develop a more comprehensive understanding of how—as opposed to why— such failures occur. We deconstructed 50 wrongful convictions and other criminal investigative failures in order to identify the major causal factors, their characteristics and interrelationships, and the systemic nature of the overall failure. We focus on the central role played by confirmation bias and other thinking errors.

Keywords: wrongful convictions, criminal investigative failures, police investigations, sentinel event reviews