19 research outputs found
Feeling the future of eyewitness research
The authors have no conflicts of interest to disclose. The data were presented at the 2020 meeting of the Psychonomic Society. This study was supported by a grant from Arnold Ventures. The funding source had no role other than financial support.Peer reviewe
pyWitness 1.0 : A python eyewitness identification analysis toolkit
Acknowledgements We are grateful to John T. Wixted for sharing his MATLAB code for the model fits presented in this paperPeer reviewedPublisher PD
Life Without Parole Sentencing in North Carolina
What explains the puzzle of life without parole (LWOP) sentencing in the United States? In the past two decades, LWOP sentences have reached record highs, with over 50,000 prisoners serving LWOP. Yet during this same period, homicide rates have steadily declined. The U.S. Supreme Court has limited the use of juvenile LWOP in Eighth Amendment rulings. Further, death sentences have steeply declined, reaching record lows. Although research has examined drivers of incarceration patterns for certain sentences, there has been little research on LWOP imposition. To shed light on what might explain the sudden rise of LWOP, we examine characteristics of the more than 1,627 cases in which LWOP was imposed from 1995 to 2017, in North Carolina, one of the states that imposes the largest numbers of these sentences. We begin by analyzing defendant race, crime, and sentence patterns by county. We associate LWOP with homicide rates, and examine interactions between homicide, victim race, and prior LWOP sentencing. This first empirical analysis of adult LWOP sentences finds important local variations in its imposition. We find that as the homicide rate increases within a county, we observe fewer LWOP sentences. We find that fewer LWOP sentences are predicted to occur as the number of black victim homicides increase in a county, but no such relationship is found when considering the number of white victim homicides. Finally, we find a strong path dependency and concentration of LWOP sentences in counties, where counties that have imposed LWOP sentences in the past are more likely to continue to do so. These findings have implications for efforts to reconsider the most severe sentences in the U.S., and they suggest that prosecutorial discretion in seeking long sentences will be important subjects for future research and policy
ROCs in Eyewitness Identification: Instructions vs. Confidence Ratings
From the perspective of signal-detection theory, different lineup instructions may induce different levels of response bias (Clark, 2005). If so, then collecting correct and false identification rates across different instructional conditions will trace out the ROC – the same ROC that, theoretically, could also be traced out from a single instruction condition in which each eyewitness decision is accompanied by a confidence rating. We tested whether the two approaches do in fact yield the same ROC. Participants were assigned to a confidence rating condition or to an instructional biasing condition (liberal, neutral, unbiased, or conservative). After watching a video of a mock crime, participants were presented with instructions followed by a 6-person simultaneous photo lineup. The ROCs from both methods were similar, but they were not exactly the same. These findings have potentially important policy implications for how the legal system should go about controlling eyewitness response bias
Assessing Theoretical Conclusions With Blinded Inference to Investigate a Potential Inference Crisis
Scientific advances across a range of disciplines hinge on the ability to make inferences about unobservable theoretical entities on the basis of empirical data patterns. Accurate inferences rely on both discovering valid, replicable data patterns and accurately interpreting those patterns in terms of their implications for theoretical constructs. The replication crisis in science has led to widespread efforts to improve the reliability of research findings, but comparatively little attention has been devoted to the validity of inferences based on those findings. Using an example from cognitive psychology, we demonstrate a blinded-inference paradigm for assessing the quality of theoretical inferences from data. Our results reveal substantial variability in experts’ judgments on the very same data, hinting at a possible inference crisis
US line-ups outperform UK line-ups
In the USA and the UK, many thousands of police suspects are identified by eyewitnesses every year. Unfortunately, many of those suspects are innocent, which becomes evident when they are exonerated by DNA testing, often after having been imprisoned for years. It is, therefore, imperative to use identification procedures that best enable eyewitnesses to discriminate innocent from guilty suspects. Although police investigators in both countries often administer line-up procedures, the details of how line-ups are presented are quite different and an important direct comparison has yet to be conducted. We investigated whether these two line-up procedures differ in terms of (i) discriminability (using receiver operating characteristic analysis) and (ii) reliability (using confidence–accuracy characteristic analysis). A total of 2249 participants watched a video of a crime and were later tested using either a six-person simultaneous photo line-up procedure (USA) or a nine-person sequential video line-up procedure (UK). US line-up procedure yielded significantly higher discriminability and significantly higher reliability. The results do not pinpoint the reason for the observed difference between the two procedures, but they do suggest that there is much room for improvement with the UK line-up