In the United States, less than half of all felony arrests result in convictions. This failure of arrests to come to trial is called case attrition, and most attrition occurs between arrest and filing. This study examines the differences in felony case attrition among 25 large police agencies in Los Angeles County; determines how much of the variance can be explained by differences in police practices, after crime and community characteristics are controlled for; and identifies those policies and practices that were related to higher conviction rates. The results were mixed and largely negative. The authors found that prevailing assumptions about attrition rates should be reexamined, and that statistics reflecting case-attrition patterns are not a valid basis for comparative evaluation of police departments.
Petersilia, Joan R., Allan Abrahamse, and James Q. Wilson, Police Performance and Case Attrition. Santa Monica, CA: RAND Corporation, 1987. https://www.rand.org/pubs/reports/R3515.html. Also available in print form.
Petersilia, Joan R., Allan Abrahamse, and James Q. Wilson, Police Performance and Case Attrition, Santa Monica, Calif.: RAND Corporation, R-3515-NIJ, 1987. As of October 06, 2021: https://www.rand.org/pubs/reports/R3515.html