Criminal punishment is the most palpable and ubiquitous means by which the state maintains social order. However, before it unleashes its punitive powers, the state must determine with high certitude which human behaviors amounted to criminal events, and who perpetrated them. This feat requires compliance with an intricate legal regime that constitutes the criminal justice process. The workings of this process and the accuracy of the verdicts it produces are the subject of this book.

The following three cases offer a glimpse into the operation of the criminal justice process. Peter Rose, a California man, was charged with the rape...

The criminal process is as good as the evidence on which it feeds. In all but the simplest of cases, the fact finder at trial is bound to be presented with a mixed fare, containing unknown shares of accurate and inaccurate testimonies. A central claim of the next four chapters is that the single most important determinant of evidence accuracy is the police investigation. This chapter examines the dynamic process by which evidence is sought and evaluated. It highlights the risk that investigations will arrive at faulty conclusions, even absent any malicious intent. The following three chapters examine the accuracy...

One morning in Tallahassee, Florida, a young man walked into a bank. After filling out a deposit slip, he approached the teller and asked her to cash a $10 money order made out by the United States Postal Service. The teller noticed immediately that the sum stated on the money order had been crudely altered in blue ink to $110. When she refused to cash the money order, the customer insisted that the post office had made a mistake, and showed her that the alteration was initialed. When the teller continued to rebuff the customer’s request, he became irate and...

Chapter 3 dealt with witnesses’ ability to recognize and identify the people they saw perpetrating a crime. This chapter deals with the broader range of testimony that witnesses provide about the criminal event. Event testimony typically describes what happened in terms of the time, place, statements uttered, sequence of actions, physical objects used, and numerous other factors that help determine what was perpetrated and by whom.¹

Event memory pertains to both culpability cases and identity cases. A witness’s account of the event can assist in determining the culpability of a known defendant. Correct testimony of the perpetrator’s utterance can establish...

A type of testimony that is widely used in criminal prosecutions consists of self-incriminating statements furnished by the defendants themselves. Typically these statements are made during interrogations conducted in police custody. Confessions are often the evidence of last resort, affording the only means of prosecuting cases in the absence of conventional types of evidence. It is thus not surprising that throughout history the extraction of confessions has often entailed serious abuses of a suspect’s rights and bodily integrity. U.S. Supreme Court Justice Hugo Black lamented that “The rack, the thumbscrew, the wheel, solitary confinement, protracted questioning and cross questioning …...

The preceding four chapters dealt with the investigative phase of the criminal justice process. This chapter and the next deal with the complementary part of the criminal process: the adjudicative phase—both the criminal trial and, more briefly, the role of post-trial judicial review.

Trials are the most symbolic embodiment of the rule of law. The U.S. Supreme Court has portrayed the criminal trial as a “decisive and portentous”¹ and “paramount” event.² Trials are considered “the central institution of law as we know it,”³ the crown jewel of the legal system.⁴ Amidst its multiple purposes, the essential objective of the...

The preceding chapter examined a range of difficulties that hinder fact finders’ ability to draw correct inferences from the evidence presented at trials of difficult cases. It must be conceded that much of that discussion was limited to human performance under somewhat decontextualized circumstances. Legal fact-finding might look different—and possibly better—when it is embedded in the institutional context of the legal process. The adjudicative process offers a number of mechanisms that are said to safeguard the accuracy of the verdicts. The ubiquitous reverence accorded the American criminal trial is premised on the assumption that these mechanisms perform their...

The central observation that emerges from this book is that our understanding of the criminal justice process can be enriched by an appreciation for the psychological strengths and limitations of the people entrusted with its operation. Criminal verdicts can be no more accurate than the human input into the process that makes them possible. Chapters 2–5 focused on the investigative phase, which is the birthplace of the core problem that plagues the process: the questionable accuracy of the evidence on which criminal verdicts are based.

Chapter 2 examined the dynamic nature of investigations, by which facts are gradually accumulated...