Expert Biases in Criminal Investigations of Sexual Offenses

Forensic and other legal experts are expected to make impartial and objective judgements in criminal investigations, including those of sexual offenses. However, in the course of the investigation, experts can be biased (e.g., when they are exposed to irrelevant information, such as the clothing and attractiveness of the victim; or by their involvement in the case and motivations that taint their judgments). These factors can then bias their observations and subsequent decision making, as well as impact the entire investigation (e.g., suggestive and leading questions in interviewing victims of sexual abuse). Such events are not isolated; they often cause bias cascade and bias snowball that contaminate the entire investigation. This chapter first reviews research regarding different sources of bias in expert decision making and then discusses their specific applications in sexual offense investigations. Finally, practical implications and recommendations to minimize biases are provided.