An Investigation of Homicide and Aggravated Assault Rates in Relation to Police Attrition

Between January 2021 and December 2022, a surge in retirements and resignations among U.S. police departments coincided with a notable rise in violent crime in urban areas. This correlational study used a retrospective approach to test the theory that a correlation existed between the unprecedented attrition of sworn officers following the 2020 social unrest and the contemporaneous sudden spike in violent crime rates in major cities during that same period. In addition, this study aimed to explore whether the four cities reacted similarly and simultaneously during the 24 months under study. The population under study was the attrition rates of the four largest urban police departments, the New York Police Department (NYPD), Chicago Police Department (CPD), Los Angeles Police Department (LAPD), and Philadelphia Police Department (PPD), and their city’s homicide and aggravated assault rates. Two decades of attrition and crime data from four major cities (New York, Los Angeles, Chicago, and Philadelphia) were analyzed to establish context for the examined 24 months. The relationship between attrition and crime data was explored using Pearson’s correlation coefficient (r) and Spearman’s rho utilizing SPSS v.28. The similarity of the cities was analyzed using Kruskal-Wallis test. This study was designed to provide insights into the complex dynamics between law enforcement manpower and urban crime rates and add to the literature on the uniqueness of urban crime.