How Much Time Should the Police Spend at Crime Hot Spots? Answers from a Police Agency Directed Randomized Field Trial in Sacramento,California

Hot spots policing has been shown to be an effective strategy for reducing crime across a number of rigorous evaluations, but despite this strong body of research, there still exist gaps in our knowledge of how officers can best respond to hot spots. We report on a randomized experiment in Sacramento, California that begins to address these gaps by testing the recommendation from prior research that police officers randomly rotate between hot spots, spending about 15?min patrolling in each. Our results suggest significant overall declines in both calls for service and crime incidents in the treatment hot spots relative to the controls. Additionally, the study was carried out primarily by the Sacramento Police Department without any outside funding. In an era of limited economic resources for policing, this experiment suggests a model by which police agencies can take ownership of science and oversee the implementation and evaluation of evidence-based interventions.     

CAN HOT SPOTS POLICING REDUCE CRIME IN URBAN AREAS? AN AGENT‐BASED SIMULATION*

Over the past two decades, there has been a growing consensus among researchers that hot spots policing is an effective strategy to prevent crime. Although strong evidence exists that hot spots policing will reduce crime at hot spots without immediate spatial displacement, we know little about its possible jurisdictional or large‐area impacts. We cannot isolate such effects in previous experiments because they (appropriately) compare treatment and control hot spots within large urban communities, thus, confounding estimates of area‐wide impacts. An agent‐based model is used to estimate area‐wide impacts of hot spots policing on street robbery. We test two implementations of hot spots policing (representing different levels of resource allocation) in a simulated borough of a city, and we compare them with two control conditions, one model with constant random patrol and another with no police officers. Our models estimate the short‐ and long‐term impacts on large‐area robbery levels of these different schemes of policing resources. These experiments reveal statistically significant effects for hot spots policing beyond both a random patrol model and a landscape without police. These simulations suggest that wider application of hot spots policing can have significant impacts on overall levels of crime in urban areas.     

Location,location, location: Interdistrict and intercircuit variation in sentencing outcomes for federal drug-trafficking offenses

Research on sentencing has made clear that factors beyond case and offenders' attributes influence court decisions. Environmental and procedural characteristics also significantly affect the sentences of criminal courts. Yet, while state-level studies regularly control for such factors, most research on modern federal determinate sentencing has neglected jurisdictional attributes and variation as sources of extralegal sentence disparity. Using the organizational context and social worlds theoretical perspectives with a multilevel analytical approach, this study assessed how district and circuit of adjudication affect case-level lengths of sentences for federal drug-trafficking offenses, finding that both significantly affect sentencing outcomes and their predictors.     

THE LAW OF CRIME CONCENTRATION AND THE CRIMINOLOGY OF PLACE*

According to Laub (2004), criminology has a developmental life course with specific turning points that allow for innovations in how we understand and respond to crime. I argue that criminology should take another turn in direction, focusing on microgeographic hot spots. By examining articles published in Criminology, I show that only marginal attention has been paid to this area of study to date—often termed the criminology of place. I illustrate the potential utility of a turning point by examining the law of crime concentration at place, which states that for a defined measure of crime at a specific microgeographic unit, the concentration of crime will fall within a narrow bandwidth of percentages for a defined cumulative proportion of crime. By providing the first cross‐city comparison of crime concentration using a common geographic unit, the same crime type, and examining a general crime measure, I find strong support for a law of crime concentration. I also show that crime concentration stays within a narrow bandwidth across time, despite strong volatility in crime incidents. By drawing from these findings, I identify several key research questions for future study. In conclusion, I argue that a focus on the criminology of place provides significant opportunity for young scholars and has great promise for advancing criminology as a science.     

TRAJECTORIES OF CRIME AT PLACES: A LONGITUDINAL STUDY OF STREET SEGMENTS IN THE CITY OF SEATTLE*

Studies of crime at micro places have generally relied on cross‐sectional data and reported the distributions of crime statistics over short periods of time. In this paper we use official crime data to examine the distribution of crime at street segments in Seattle, Washington, over a 14‐year period. We go beyond prior research in two ways. First, we view crime trends at places over a much longer period than other studies that have examined micro places. Second, we use group‐based trajectory analysis to uncover distinctive developmental trends in our data. Our findings support the view that micro places generally have stable concentrations of crime events over time. However, we also find that a relatively small proportion of places belong to groups with steeply rising or declining crime trajectories and that these places are primarily responsible for overall city trends in crime. These findings are particularly important given the more general decline in crime rates observed in Seattle and many other American cities in the 1990s. Our study suggests that the crime drop can be understood not as a general process that occurred across the city landscape but one that was generated in a relatively small group of micro places with strong declining crime trajectories over time.     

Hot spots policing and crime prevention: A systematic review of randomized controlled trials

Crime scholars and practitioners have argued that police actions should be focused on high-risk crime places rather than spread thinly across the urban landscape. This review examines five randomized controlled trials of the effects of concentrating police enforcement efforts on crime hot spots. The findings of these evaluations suggest that focused police actions can prevent crime and disorder in crime hot spots. A meta-analysis of the effect sizes from the five experiments reveals a statistically significant mean effect size for hot spots policing interventions; this suggests overall reductions in citizen calls for service in the treatment hot spots relative to the control hot spots. These studies also suggest that focused police actions at specific locations do not necessarily result in crime displacement. Although these evaluations reveal that these programs work in preventing crime, additional research is needed to unravel other important policy-relevant issues such as community reaction to focused police enforcement efforts.     

DOES CRIME JUST MOVE AROUND THE CORNER? A CONTROLLED STUDY OF SPATIAL DISPLACEMENT AND DIFFUSION OF CRIME CONTROL BENEFITS*

Recent studies point to the potential theoretical and practical benefits of focusing police resources on crime hot spots. However, many scholars have noted that such approaches risk displacing crime or disorder to other places where programs are not in place. Although much attention has been paid to the idea of displacement, methodological problems associated with measuring it have often been overlooked. We try to fill these gaps in measurement and understanding of displacement and the related phenomenon of diffusion of crime control benefits. Our main focus is on immediate spatial displacement or diffusion of crime to areas near the targeted sites of an intervention. Do focused crime prevention efforts at places simply result in a movement of offenders to areas nearby targeted sites—“do they simply move crime around the corner”? Or, conversely, will a crime prevention effort focusing on specific places lead to improvement in areas nearby—what has come to be termed a diffusion of crime control benefits? Our data are drawn from a controlled study of displacement and diffusion in Jersey City, New Jersey. Two sites with substantial street‐level crime and disorder were targeted and carefully monitored during an experimental period. Two neighboring areas were selected as “catchment areas” from which to assess immediate spatial displacement or diffusion. Intensive police interventions were applied to each target site but not to the catchment areas. More than 6,000 20‐minute social observations were conducted in the target and catchment areas. They were supplemented by interviews and ethnographic field observations. Our findings indicate that, at least for crime markets involving drugs and prostitution, crime does not simply move around the corner. Indeed, this study supports the position that the most likely outcome of such focused crime prevention efforts is a diffusion of crime control benefits to nearby areas.     

Can Making It Harder to Convict Criminals Ever Reduce Crime?

This paper attempts to find the optimal level of the burden of proof needed in criminal cases in order to minimize crime. It also aims to provide an explanation for the higher burden of proof required in criminal cases than civil cases. It assumes that police officers receive incentive payments for convictions in cases they investigate. Although the direct effect of a higher burden of proof requirement is to reduce the probability of conviction, the indirect effect is to force police officers to build stronger cases and put more effort into finding suspects who are more likely to be guilty. Moreover, the increase in the marginal probability of conviction potential criminals face when they actually commit a crime increases. These factors imply that a reduction in the burden of proof will not necessarily reduce crime.     

犯罪侦查中的欺骗：在合法与非法之间

犯罪侦查是具有极强对抗性和博弈性的活动,在犯罪侦查中并不绝对地排斥在一些特殊条件下使用带欺骗因素的手段。在合理范围内使用这类侦查手段具有一定的法律许容性。为防止其被滥用,应设定若干限制性原则予以规范。     

Could Innovations in Policing have Contributed to the New York City Crime Drop even in a Period of Declining Police Strength?: The Case of Stop,Question and Frisk as a Hot Spots Policing Strategy

Available data make it impossible to reach strong conclusions about the role of policing in the New York crime decline. Instead, we examine whether innovations implemented in New York fit with what is known about effective policing strategies. Our main analysis focuses on how the New York City Police Department (NYPD) could have continued to contribute to the crime drop over the last decade when the number of police declined significantly. We examine geographic data on crime and stop, question and frisks (SQFs) to show that SQFs are concentrated at crime hot spots. We also show that the NYPD increased these specific hot spots policing strategies despite declining numbers. In our discussion, we speculate on whether this “doing more with less” could be an explanation for the continued crime drop in New York, noting the limitations of drawing conclusions from existing data. We also raise concerns about possible backfire effects of SQF hot spots approaches.     

Using National Incident-Based Reporting System Data for Strategic Crime Analysis

The utility of the National Incident-Based Reporting System (NIBRS) forstrategic crime analysis has yet to be explored. The NIBRS represents anadvancement over existing reporting systems and possesses considerableutility to frontline law enforcement with respect to strategic crimeanalysis. This paper discusses the utility of the NIBRS for identifyinglocal and regional trends in narcotics related offenses. As an example, weselected four localities from the 1997 Virginia NIBRS data to examine trendsin the sale/distribution and possession of narcotics. Our analysis showsthat the NIBRS provides significantly more incident-related detail than hasheretofore been available for strategic crime analysis at the regional orstate level. Moreover, the NIBRS provides neighboring communities theopportunity to compare information on emerging crime patterns and criminalenterprises which extend beyond local boundaries. Finally, enhancing localreporting compliance by highlighting the strategic utility of the data tolocal law enforcement will ultimately ensure the quality of the data set,which can then be employed by larger entities as well as criminal justiceresearchers for policy development and planning.     

DOES UNDOCUMENTED IMMIGRATION INCREASE VIOLENT CRIME?*

Despite substantial public, political, and scholarly attention to the issue of immigration and crime, we know little about the criminological consequences of undocumented immigration. As a result, fundamental questions about whether undocumented immigration increases violent crime remain unanswered. In an attempt to address this gap, we combine newly developed estimates of the unauthorized population with multiple data sources to capture the criminal, socioeconomic, and demographic context of all 50 states and Washington, DC, from 1990 to 2014 to provide the first longitudinal analysis of the macro‐level relationship between undocumented immigration and violence. The results from fixed‐effects regression models reveal that undocumented immigration does not increase violence. Rather, the relationship between undocumented immigration and violent crime is generally negative, although not significant in all specifications. Using supplemental models of victimization data and instrumental variable methods, we find little evidence that these results are due to decreased reporting or selective migration to avoid crime. We consider the theoretical and policy implications of these findings against the backdrop of the dramatic increase in immigration enforcement in recent decades.     

吉林省行政执法热点、难点问题解析与对策研究

在深化行政执法体制改革的大背景下,准确把握当前吉林省行政执法工作中面临的热点、难点问题,认真剖析其原因,最终做到对症下药,既有利于不断提升全省依法行政的质量和水平,也有利于将法治吉林建设不断推向深入.     

DOES WHAT POLICE DO AT HOT SPOTS MATTER? THE PHILADELPHIA POLICING TACTICS EXPERIMENT*

Policing tactics that are proactive, focused on small places or groups of people in small places, and tailor specific solutions to problems using careful analysis of local conditions seem to be effective at reducing violent crime. But which tactics are most effective when applied at hot spots remains unknown. This article documents the design and implementation of a randomized controlled field experiment to test three policing tactics applied to small, high‐crime places: 1) foot patrol, 2) problem‐oriented policing, and 3) offender‐focused policing. A total of 81 experimental places were identified from the highest violent crime areas in Philadelphia (27 areas were judged amenable to each policing tactic). Within each group of 27 areas, 20 places were randomly assigned to receive treatment and 7 places acted as controls. Offender‐focused sites experienced a 42 percent reduction in all violent crime and a 50 percent reduction in violent felonies compared with their control places. Problem‐oriented policing and foot patrol did not significantly reduce violent crime or violent felonies. Potential explanations of these findings are discussed in the contexts of dosage, implementation, and hot spot stability over time.