The Reliability of Pattern Classification in Bloodstain Pattern Analysis,Part 1: Bloodstain Patterns on Rigid Non‐absorbent Surfaces

This study was designed to produce the first baseline measure of reliability in bloodstain pattern classification. A panel of experienced bloodstain pattern analysts examined over 400 spatter patterns on three rigid non‐absorbent surfaces. The patterns varied in spatter type and extent. A case summary accompanied each pattern that either contained neutral information, information to suggest the correct pattern (i.e., was positively biasing), or information to suggest an incorrect pattern (i.e., was negatively biasing). Across the variables under examination, 13% of classifications were erroneous. Generally speaking, where the pattern was more difficult to recognize (e.g., limited staining extent or a patterned substrate), analysts became more conservative in their judgment, opting to be inconclusive. Incorrect classifications increased as a function of the negatively biasing contextual information. The implications of the findings for practice are discussed.     

Taking Threat Seriously: Prejudice,Principle, and Attitudes Toward Racial Policies

Drawing from group theories of race-related attitudes and electoral politics, we develop and test how anxiety influences the relative weight of prejudice as a determinant of individuals’ support for racial policies. We hypothesize that prejudice will more strongly influence the racial policy preferences of people who are feeling anxious than it will for people who are not. Using an experimental design we manipulate subjects’ levels of threat and find significant treatment effects, as hypothesized. We find that individuals’ racial policy attitudes are partially conditional on their affective states: individuals who feel anxious report less support for racial policies than those individuals who do not feel anxious, even when this threat is stimulated by non-racial content. More broadly, we conclude that affect is central to a better understanding of individuals’ political attitudes and behaviors.     

Interviewing Witnesses: The Effect of Forced Confabulation on Event Memory

After viewing a crime video, participants answered 16 answerable and 6 unanswerable questions. Those in the "voluntary guess" condition had a "don't know" response option; those in the "forced guess" condition did not. One week later the same questions were answered with a "don't know" option. In both experiments, information generated from forced confabulation was less likely remembered than information voluntarily self-generated. Further, when the same answer was given to an unanswerable question both times, the confidence expressed in the answer increased over time in both the forced and the voluntary guess conditions. Pressing eyewitnesses to answer questions, especially questions repeated thrice (Experiment 2), may not be an effective practice because it reliably increases intrusion errors but not correct recall.