The retrospective detective: Cognitive bias and the cold case investigation

Abstract

Much of the available research on police decision-making in criminal investigations tends to focus on the detrimental effects of cognitive bias in live/current homicide investigations, and not on how it might have a negative influence on investigative decision-making in cold case homicides. This arguably indicates the existence of a common assumption that, live or cold, criminal investigations require the same decision-making and so are vulnerable to the same bias and in the same ways. This chapter suggests that the very term 'cold case' is likely to have a different psychological bias effect on investigators of cold cases and to pose potentially a far stronger negative influence on the decisions that are made in cold as opposed to live cases. The idea that cold cases necessitate a different 'investigative mindset' to live cases is posited here, along with the suggestion that investigator confidence is likely to be undermined by an inherent framing effect which comes into play when people are told that they are to investigate a cold case, that does not with live cases. Also discussed are the implications of having to make decisions based on the result of numerous previous decisions made by prior police investigators, might have on coldcase investigators. This may in turn serve to increase the likelihood of confirmation bias when investigators review cold cases as they make decisions within a far more pessimistic frame than they do for live cases. The chapter ends with a tentative research agenda for increasing our understanding of decision-making processes in cold case homicide investigations.