The Impact of Forensic Evidence on Arrest and Prosecution

The grantee will conduct a study focused on eight of the ten research recommendations made in the Peterson, et al (2010) report. There are two phases of the study. Phase one will analyze a random sample of approximately 2,500 case files from 2006 through 2009 that contain forensic analyses from the Connecticut State Forensic Science Laboratory, along with corresponding police and prosecutorial case files. The goal of the proposed research is to further our understanding of how the presence of forensic evidence relates to case clearance and conviction. As with Peterson, et al. (2010), this research has four research objectives: 1) estimate the percentage of cases in which crime scene evidence is collected; 2) discover what kinds of forensic evidence are being collected; 3) track such evidence through the criminal justice system; and 4) identify which forms of forensic evidence are most efficacious given the crime investigated. The research instrument to be used in the coding of these case files is a slightly modified version of the instrument used by Peterson, et al. This instrument records up to 40 variables in three separate categories: forensic, criminal offense, and crime disposition. The proposed study will also introduce two variables not recorded in the previous study: did any available witness name a suspect or provide a description to police, and did the suspect make a statement. Phase two will consist of qualitative interviews regarding case files randomly selected from the sample population listed above, with approximately 270 investigative and prosecutorial personnel. These interviews will further advance our understanding of how forensic evidence affects the use of investigative and prosecutorial discretion. These interviews will be centered on four themes: the exact nature of assistance provided by physical evidence in the identification of the offender, the use of forensic evidence in the interview and interrogation process of witnesses and offenders, the utility of forensic evidence in plea negotiations, and the effect of forensic evidence on sentencing.
ca/ncf