An analysis of the sources of errors in observation and memory which flaw testimony considers the relevant findings of psychological research and draws implications for the assessment of evidence. Errors of observation caused by the crime situation itself are identified, as are errors in observation caused by the witness. How the characteristics of eyewitnesses affect their capacity to collect and present accurate evidence is also considered, along with problems associated with lying and its detection. Issues associated with suspect-identification evidence are explored, followed by a discussion of how facts about which the prosecution and defense disagree emerge before and during the trial. Attention is also given to the techniques of examining, cross-examining, and reexamining witnesses. Throughout the discussion, the book explains how evidence is assessed by the court. This theme culminates in a consideration of the factors involved in verdict decisionmaking, with a focus on consistency and inconsistency in the evidence, assessment of witnesses, mental processes in judgment, and determination of probability. Chapter references and a subject index are provided.