The majority of common law jurisdictions, and some civil law jurisdictions, use juries composed of citizens drawn from the general population to deliberate and reach collective verdicts in criminal cases. Juries are relied on to use their collective judgment to reach verdicts that accord with normative legal goals; for example, by being accurate and fair.

How Juries Work suggests that, though important symbolically, the current jury system is not necessarily well-designed to meet the demands of modern society, which increasingly requires evidence-based procedure that is carefully designed to achieve normative goals. Rebecca K. Helm proposes new models of how jurors and juries function in practice, informed by psychological theory and empirical research, which provides a framework to interpret and integrate the large body of existing work on jury decision-making. Drawing on this framework, Helm highlights the deficiencies and strengths of the jury as a legal factfinder, providing key insights into how to minimise deficiencies and maximise strengths through trial procedure. The book concludes with a set of timely evidence-based suggestions as to how procedure surrounding trial by jury might be altered to enhance the administration of justice in the many jurisdictions where the criminal law jury is utilised.

How Juries Work integrates legal and psychological theory and research to present a comprehensive assessment of the modern criminal law jury, and of how evidence-based research can improve jury performance.