DOI: 10.3886/icpsr36727.v1
title: Improving the Production and Use of Forensic Science, 5 U.S. counties, 2006-2009
title: Version 1

description: This study collection sought to thoroughly understand the creation, testing, and use of forensic science in five jurisdictions across the country. A random sample was selected of recent criminal cases in the following jurisdictions and tracked from investigation to adjudication to understand how forensic evidence functions: Sacramento County, CA: 990 cases Segwick County, KS: 936 cases Allegheny County, PA: 978 cases Bexar County (San Antonio), TX: 936 cases King County, WA: 892 cases The Principal Investigator sought answers to the following seven primary research questions: How often is forensic evidence collected and analyzed and how is it used pre-arrest? What are the outcomes of forensic evidence testing? What is the effect of forensic evidence on arrest and charging? How does forensic evidence affect the plea-bargaining process? What effect does forensic evidence have on conviction and sentencing outcomes? Does the turnaround time for analysis of forensic evidence have any impact on case disposition? Does the institutional configuration of the crime laboratory have any effect on its productivity? Data for the following types of forensic testing are included in this data collection: hair, fibers, glass, paint, gas chromatography / mass spectrometry (GC/MS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy / energy dispersive x-ray spectroscopy (SEM/EDX), physical match, drug identification, toxicology, serology, combined DNA index system (CODIS), DNA short tandem repeat (Y-STR), blood pattern, test fire, and comparison scope.
description: The project's primary goal is to better understand the effect of forensic science on the resolution and outcome of criminal cases. There was particular interest in understanding how forensic analysis affects the probability that a case progresses from one stage to the next in the criminal justice system. The Principal Investigator sought answers to the following seven primary research questions: How often is forensic evidence collected and analyzed and how is it used pre-arrest? What are the outcomes of forensic evidence testing? What is the effect of forensic evidence on arrest and charging? How does forensic evidence affect the plea-bargaining process? What effect does forensic evidence have on conviction and sentencing outcomes? Does the turnaround time for analysis of forensic evidence have any impact on case disposition? Does the institutional configuration of the crime laboratory have any effect on its productivity?
description: The five study sites were selected based on the following criteria: diverse institutional configurations of crime labs in the criminal justice system; two of the sites participating in the National Incident-Based Reporting System (NIBRS); broad range of law enforcement agencies in terms of size and geographic diversity; jurisdictions have adopted a variety of policies to prioritize forensic testing.
description: Information on over a dozen forensic tests are provided in the data file. For example the test type variables <strong>HAIRS, FIBERS, GLASS, PAINT, DRUG_ID,</strong> and <strong>TOX_ID</strong> denote if the evidence type was analyzed. For almost all forensic test types, the following three variables were also collected. <strong>TestType_RES:</strong> Result of evidence analysis. <strong>TestType_REQUEST_DATES: </strong> Date of first request for analysis. <strong>TestType_REPORT_DATES:</strong> Date of first report of analysis Beyond these, some of the forensic test types had additional associated variables. Other variables include basic background information for each reported crime (case) such as when and where the crime occurred, demographic information (age, gender, and race) on both victim and arrestee, and the disposition of the case (i.e., dismissed, plea agreement, conviction).
description: None
description: Presence of Common Scales: None
description: For each site, the Principal Investigator sought to collect a random sample of 200 cases for each of four crimes: aggravated assault, burglary, rape, and robbery. These cases were generated from each law enforcement agency's comprehensive listing of reported crimes that occurred between 2007 and 2009. Because homicide is a less common event every recorded murder over the three-year period was requested for all study sites. In all five jurisdictions the calendar year 2006 was added to increase the homicide sample size and the number of fully adjudicated cases.
description: Datasets: DS1: Improving the Production and Use of Forensic Science, 5 U.S. counties, 2006-2009
description: Reported criminal cases of aggravated assault, burglary, murder, rape, and robbery within the counties of Allegheny (PA), Bexar (TX), King (WA), Sacramento (CA), and Sedgwick (KS) between the years 2006-2009. Smallest Geographic Unit: County
description: record abstractsThe Principal Investigator planned for each of the five surveyed counties to account for approximately 20% of the 4,732 total cases. Also part of the plan was for the five primary crime types of interest (aggravated assault, burglary, murder, rape, and robbery) to account for 20% of the cases in the data file. The desired result was to have roughly 200 cases per county per crime type.The Principal Investigator has noted an important limitation within the data Each jurisdiction sampled followed their own procedures for collecting and capturing forensic evidence. Therefore, some of the data, or types of forensic testing, were not available from each county. The following is a list of which study jurisdictions <strong>DID NOT</strong> have data available for a particular topic. <strong>Forensic evidence collected:</strong> Allegheny <strong>Witness reports:</strong> King, Sacramento, Sedgwick <strong>Fingerprint comparison:</strong> Allegheny, Bexar, Sedgwick <strong>Toxicology analysis:</strong> Bexar, King <strong>Combined DNA index system (CODIS) entry/result:</strong> Allegheny In addition to the raw data file approved restricted-data access users will receive a Stata syntax file (.do) provided by the Principal Investigator. This file documents the rationale and procedures for recoding variables performed during analysis.This specific data collection was one of four overlapping studies conducted by the Principal Investigator regarding forensic evidence in the criminal justice system. The other three areas of data collected, but not associated with this specific data collection, included: qualitative interviews with law enforcement, forensic scientists, and district attorneys to understand how forensic evidence is created and used; analyzed data collected in the Bureau of Justice Statistics censuses of crime labs in the United States in order to determine what effects, if any, payment system and organizational structure had on laboratory productivity and public safety impact; and conducted a study of a sample of prosecutors and defense counsel with experimental manipulations to understand how forensic evidence affected the perceived strength of the case during plea bargaining.