The purpose of the study was to assess how the strength of eyewitness evidence affects plea bargaining decisions by prosecutors and defense attorneys.
Surveys were administered to 93 defense attorneys and 46 prosecutors from matched counties in California. On the questionnaire, each participant was asked four background questions and read four versions of a crime scenario (counterbalanced across participants for order of presentation) in which two specific eyewitness factors -- (a) same- versus cross-race identification and (b) prior contact or not -- were experimentally manipulated in a factorial design. Specifically, the study design was a two (prosecutor versus defense attorney) by two (familiar versus unfamiliar suspect) by two (same-race versus cross-race identification) mixed factor design with only the first factor varied between subjects. The scenarios described a store robbery in which identification by one eyewitness was the only evidence against the defendant. The four scenarios were identical except for the slight wording changes required to vary the familiarity condition (the eyewitness had seen the suspect previously or this was not mentioned) and the cross-race condition. After reading each scenario, attorneys were asked to respond to five questions in light of the facts presented. Participants were given the option to complete the test materials online or using hard copies; most used the hard copy option.
This study utilized a convenience sample; the data were collected from county offices of the District Attorney and Public Defender in the state of California. Because the questionnaire included questions about sentencing, and sentencing guidelines vary by state in the United States, it was necessary to restrict data collection to one state. In the data collection phase, over a period of 18-months, email, telephone, and postal mail were used to contact repeatedly, the head District Attorney and Public Defender in each of the 58 counties in California, to request the participation of the Deputy District Attorneys and Deputy Public Defenders in their county. Only the data from counties in which there were completed test materials from both the offices of the District Attorney and the Public Defender were included in this study. This was done to match the two samples, at least in terms of the counties in which they served. These included 8 counties, contributing a total of 93 Deputy Public Defenders and 46 District Attorneys. Within each county, it was simply required that each participant had had felony trial experience.
All Deputy District Attorneys and Deputy Public Defenders in the state of California between February 2010 and June 2011.
Surveys administered to prosecutors and defense attorneys in the state of California between February 2010 and June 2011.
The study contains 28 variables including background data on the study participants and responses to questions relating to four crime scenarios that differ in terms of the details of the eyewitness evidence. Background variables include attorney type (public defender or prosecutor), number of years as a trial attorney, number of cases tried, number of cases involving eyewitness cases, and percent of cases typically settled through plea bargaining. Variables from the crime scenarios measure whether the respondents would plea bargain the case, the lowest/highest plea bargain they would offer/accept, and their estimate of the probability that the defendant was guilty and the probability that they would win the case if it went to trial.
Response rate information is not available.
The data include variables that use a continuous response scale from 0 percent to 100 percent and variables that use a response scale of 7 potential plea bargain offers ranging from "No plea" to "One strike 5-years".