The Great American Crime Decline : Possible Explanations

This chapter examines the most important features of the crime decline in the United States during the 1990s-2010s but also takes a broader look at the violence declines of the last three centuries. The author argues that violent and property crime trends might have diverged in the 1990s, with property crimes increasingly happening in the online sphere and thus traditional property crime statistics not being reflective of the full picture. An important distinction is made between ‘contact crimes’ and crimes that do not require a victim and offender to be present in the same physical space. Contrary to the uncertainties engendered by property crime, the declines in violent (‘contact’) crime are rather general, and have been happening not only across all demographic and geographic categories within the United States but also throughout the developed world. An analysis of research literature on crime trends has identified twenty-four different explanations for the crime drop. Each one of them is briefly outlined and examined in terms of conceptual clarity and empirical support. Nine crime decline explanations are highlighted as the most promising ones. The majority of these promising explanations, being relative newcomers in the crime trends literature, have not been subjected to sufficient empirical scrutiny yet, and thus require further research. One potentially fruitful avenue for future studies is to examine the association of the most promising crime decline explanations with improvements in self-control

Measuring UK crime gangs: a social network problem

This paper describes the output of a study to tackle the problem of gang-related crime in the UK; we present the intelligence and routinely-gathered data available to a UK regional police force, and describe an initial social network analysis of gangs in the Greater Manchester area of the UK between 2000 and 2006. By applying social network analysis techniques, we attempt to detect the birth of two new gangs based on local features (modularity, cliques) and global features (clustering coefficients). Thus for the future, identifying the changes in these can help us identify the possible birth of new gangs (sub-networks) in the social system. Furthermore, we study the dynamics of these networks globally and locally, and have identified the global characteristics that tell us that they are not random graphs—they are small world graphs—implying that the formation of gangs is not a random event. However, we are not yet able to conclude anything significant about scale-free characteristics due to insufficient sample size. A final analysis looks at gang roles and develops further insight into the nature of the different link types, referring to Klerks' 'third generation' analysis, as well as a brief discussion of the potential UK policy applications of this work

Saving Human Lives: What Complexity Science and Information Systems can Contribute

We discuss models and data of crowd disasters, crime, terrorism, war and disease spreading to show that conventional recipes, such as deterrence strategies, are often not effective and sufficient to contain them. Many common approaches do not provide a good picture of the actual system behavior, because they neglect feedback loops, instabilities and cascade effects. The complex and often counter-intuitive behavior of social systems and their macro-level collective dynamics can be better understood by means of complexity science. We highlight that a suitable system design and management can help to stop undesirable cascade effects and to enable favorable kinds of self-organization in the system. In such a way, complexity science can help to save human lives.Comment: 67 pages, 25 figures; accepted for publication in Journal of Statistical Physics [for related work see http://www.futurict.eu/

Changing the street dynamic evaluating Chicago's group violence reduction strategy

Research Summary: This study uses a quasi-experimental design to evaluate the efficacy of Chicago's Group Violence Reduction Strategy (VRS), a gun violence reduction program that delivers a focused-deterrence and legitimacy-based message to gang factions through a series of hour-long "call-ins." The results suggest that those gang factions who attend a VRS call-in experience a 23% reduction in overall shooting behavior and a 32% reduction in gunshot victimization in the year after treatment compared with similar factions. Policy Implications: Gun violence in U.S. cities often is concentrated in small geographic areas and in small networks of group or gang-involved individuals. The results of this study suggest that focused intervention efforts such as VRS can produce significant reductions in gun violence, but especially gunshot victimization, among gangs. Focused programs such as these offer an important alternative to broad-sweeping practices or policies that might otherwise expand the use of the criminal justice system

Police violence and citizen crime reporting in the black community

High-profile cases of police violence—disproportionately experienced by black men—may present a serious threat to public safety if they lower citizen crime reporting. Using an interrupted time series design, this study analyzes how one of Milwaukee’s most publicized cases of police violence against an unarmed black man, the beating of Frank Jude, affected police-related 911 calls. Controlling for crime, prior call patterns, and several neighborhood characteristics, we find that residents of Milwaukee’s neighborhoods, especially residents of black neighborhoods, were far less likely to report crime after Jude’s beating was broadcast. The effect lasted for over a year and resulted in a total net loss of approximately 22,200 calls for service. Other local and national cases of police violence against unarmed black men also had a significant impact on citizen crime reporting in Milwaukee. Police misconduct can powerfully suppress one of the most basic forms of civic engagement: calling 911 for matters of personal and public safety