Showing papers in "Crime Science in 2017"

How concentrated is crime at places? A systematic review from 1970 to 2015

Abstract: Despite the increasing awareness and interests about the importance of crime concentration at places, scholars have not comprehensively synthesized the body of evidence related to this thesis We conduct a systematic review and meta-analysis of the evidence that crime is concentrated among places We identified 44 studies that empirically examined crime concentration at place and provided quantitative information sufficient for analysis We organized data using visual binning and fitted logarithmic curves to the median values of the bins We examine concentration in two conditions: when all places are studied (prevalence), and when only places with at least one crime are studied (frequency) We find that crime is concentrated at a relatively few places in both conditions We also compared concentration for calls for services to reported crime incidents Calls for services appear more concentrated than crime at places Because there are several ways place is defined, we compared different units of analysis Crime is more concentrated at addresses than other units, including street segments We compared crime concentration over time and found less concentration in 2000s compared to 1980s and 1990s We also compared crime concentration between US and non-US countries and found more concentration in US Finally, violent crime is more concentrated than property crime Though we systematically reviewed a comprehensive list of studies, summarizing this literature is problematic Not only should more systematic reviews be conducted as more research becomes available, but future inquiries should examine other ways of summarizing these studies that could challenge our findings

Wildlife crime: a conceptual integration, literature review, and methodological critique

Abstract: Wildlife crime, including poaching and wildlife trafficking, threaten the existence of particular species. To date, research on wildlife crime has been primarily conducted by those with backgrounds in the biological sciences, however crime scientists, have much to offer in examining wildlife crimes. With this in mind, we aim to highlight general principals of crime science found through an in-depth review of the conservation literature. More specifically, to determine if, and how, different types of wildlife crimes cluster, to identify the existence of interventions for which the mechanisms mirror those found within SCP, and consider their effectiveness. Our review suggests that various types of wildlife crimes concentrate in time and space, among products, along certain routes, and at particular facilities. Further, some overlap exists between mechanisms used to mitigate more traditional crimes and those used to prevent wildlife crimes and protect threatened species. Of note are the attempts by those in the conservation community to increase the risk of crime, remove excuses for non-compliance of rules, and reduce provocations that contribute to particular types of wildlife crime. Given this overlap crime scientists may be able to collaborate with conservationists to draw on the extensive knowledge base of prevention studies to identify potential interventions, analyze their implementation, and evaluate the overall impact of an intervention.

Drug supply networks: a systematic review of the organizational structure of illicit drug trade

Abstract: This study presents a systematic review of research using social network analysis to document the structure of organized crime groups involved in drug trafficking. Our first objective is to determine whether the balance of evidence supports the argument that organized crime groups are loosely structured. Second, we aim to assess the relative importance of targeting individuals high in social capital (structural position) versus human capital (access to resources) in efforts to disrupt operations. Examining 34 studies, describing 54 illicit drug supply networks, we find five implications for anti-drug policy, and propose seven recommendations to facilitate meta-analysis and improve cross-network comparison.

Ravenous wolves revisited: a systematic review of offending concentration

Abstract: Numerous studies have established that crime is highly concentrated among a small group of offenders. These findings have guided the development of various crime prevention strategies. The underlying theme of these strategies is that by focusing on the few offenders who are responsible for most of the crime, we can prevent the greatest amount of crime with the fewest resources. Nevertheless, there has been no systematic review of the many studies, so it is possible that the accepted understanding among researchers and practitioners is based on a few prominent studies that are misleading. Further, we do not know how concentrated crime is among offenders, given the variety of ways researchers report their findings. This paper systematically reviews this literature and uses meta-analysis to determine how confident we can be that crime is concentrated among a few offenders. We first systematically reviewed the literature and found 73 studies on the concentration of crime among offenders. From those studies, we identified 15 studies on the prevalence of offending and 27 studies on the frequency of offending that provided data suitable for analysis. We then performed a meta-analysis of those studies to examine how crime is concentrated among the worst offenders and how that concentration varies between different types of offenders. We found that crime is highly concentrated in the population and across different types of offenders. Little variation in concentration exists between youths and adults or between American offenders and those from other countries. We found more variation between males and females in the concentration of offending, though we believe this may be due to the more limited data on female offenders. The systematic review and meta-analysis we present here is the first study of its kind on offending concentration. This is an important step in closing this gap in the crime prevention literature, but we encourage making updates to this systematic review as new literature becomes available, and using alternate methods of summarizing these studies that could challenge these findings.

Crime topic modeling

Abstract: The classification of crime into discrete categories entails a massive loss of information. Crimes emerge out of a complex mix of behaviors and situations, yet most of these details cannot be captured by singular crime type labels. This information loss impacts our ability to not only understand the causes of crime, but also how to develop optimal crime prevention strategies. We apply machine learning methods to short narrative text descriptions accompanying crime records with the goal of discovering ecologically more meaningful latent crime classes. We term these latent classes ‘crime topics’ in reference to text-based topic modeling methods that produce them. We use topic distributions to measure clustering among formally recognized crime types. Crime topics replicate broad distinctions between violent and property crime, but also reveal nuances linked to target characteristics, situational conditions and the tools and methods of attack. Formal crime types are not discrete in topic space. Rather, crime types are distributed across a range of crime topics. Similarly, individual crime topics are distributed across a range of formal crime types. Key ecological groups include identity theft, shoplifting, burglary and theft, car crimes and vandalism, criminal threats and confidence crimes, and violent crimes. Though not a replacement for formal legal crime classifications, crime topics provide a unique window into the heterogeneous causal processes underlying crime.

How concentrated is crime among victims? A systematic review from 1977 to 2014

Abstract: Considerable research shows that crime is concentrated among a few victims. However, no one has systematically compared these studies to determine the level of concentration and its variation across studies. To address this void in our knowledge of repeat victimization, we conducted a systematic review and meta-analysis of the evidence that crime is concentrated among victims. We distinguished between studies of victimization prevalence, which examine both victims and non-victims, and studies of victimization frequency, which only examine subjects that were victimized once or more. We identified 20 prevalence studies and 20 frequency studies that provided quantitative information sufficient for analysis. We organized data using visual binning and fitted logarithmic curves to the median values of the bins. We found that crime is concentrated within a small proportion of the subjects in both the prevalence studies and frequency studies, but also that it is more concentrated in the former. When we compared studies of business victimization to studies of household victimization, we found that victimization is more concentrated among households than among businesses in prevalence studies, but that the reverse is true for frequency studies. A comparison between personal and property victimizations shows that the patterns of re-victimizations are similar. Crime is more concentrated in the United States compared to the United Kingdom in prevalence studies, but the opposite is true when frequency studies are examined. Finally, the concentration of victimization changes over time for both the US and the UK, but the nature of that change depends on whether one is examining prevalence or frequency studies. Not surprisingly, our systemic review supports the notion that a large proportion of victimizations are of a relatively small portion of the population and of a small portion of all those victimized at least once. There is no question that crime is concentrated among a few victims. However, there is also variation in concentration that we also explored.

Compared to what? Estimating the relative concentration of crime at places using systematic and other reviews

Abstract: That crime is concentrated at a few places is well established by over 44 studies. This is true whether one examines addresses or street segments. Additionally, crime is concentrated among offenders and victims. Many physical, biological, and social phenomena are concentrated as well. This raises a question: is crime more or less concentrated at places than other phenomena? If it is not, then crime concentration maybe the result of standard ubiquitous processes that operate in nature. If crime is more or is less concentrated than other phenomena, then researchers need to ask why. We synthesize results from three systematic reviews and review other literatures to provide preliminary answers. We find that although crime is more concentrated at addresses than other spatial units, this is due to the fact that more addresses have no crime than is true of larger units. When only places with one or more crimes are examined, place crime is no more concentrated than other spatial unit crime. Crime appears to be concentrated at places at about the same level as it is concentrated among offenders or victims. And crime concentration does not appear to be peculiarly concentrated compared to non-crime related phenomena. The concentration of crime at places is unexceptional, and should be treated as one manifestation of a general tendency of things to be concentrated.

Domestic burglary drop and the security hypothesis

Abstract: This study examines the role of household security devices in producing the domestic burglary falls in England and Wales. It extends the study of the security hypothesis as an explanation for the ‘crime drop’. Crime Survey for England and Wales data are analysed from 1992 to 2011/12 via a series of data signatures indicating the nature of, and change in, the relationship between security devices and burglary. The causal role of improved security is strongly indicated by a set of interlocking data signatures: rapid increases in the prevalence of security, particularly in the availability of combinations of the most effective devices (door and window locks plus security lighting); a steep decline in the proportion of households without security accompanied by disproportionate rises in their burglary risk; and the decline being solely in forced rather than unforced entries to households. The study concludes that there is strong evidence that security caused the decline in burglary in England and Wales in the 1990s. Testing the security hypothesis across a wider range of crime types, countries and forms of security than examined to date, is required both to understand the crime drop and to derive lessons for future crime prevention practice and policy.

A systematic review of tagging as a method to reduce theft in retail environments

Abstract: Retailers routinely use security tags to reduce theft Presently, however, there has been no attempt to systematically review the literature on security tags Guided by the acronym EMMIE, this paper set out to (1) examine the evidence that tags are effective at reducing theft, (2) identify the key mechanisms through which tags are expected to reduce theft and the conditions that moderate tag effectiveness, and (3) summarise information relevant to the implementation and economic costs of tagging In this mixed-methods review, we performed systematic keyword searches of the published and unpublished literature, hand searched relevant journals, conducted forward and backward citation searches and consulted with four retailers Studies were included if they reported an explicit goal of reducing the theft or shrinkage of items through the use of security tags in retail environments We identified 50 eligible studies, eight of which reported quantitative data on the effectiveness of tags in retail environments Across these eight studies, five showed positive results associated with the introduction of tags, but heterogeneity in the type of tag and reported outcome measures precluded a meta-analysis We identified three mechanisms through which tags might plausibly reduce theft—increase the risks, reduce the rewards, increase the effort—which were found to vary by tag type, and their activation dependent on five broad categories of moderator: retail store and staff, customers (including shoplifters), tag type, product type, and the involvement of the police and criminal justice system Implementation challenges documented in the literature related mainly to staffing issues and tagging strategy Finally, although estimates are available on the costs of tagging, our searches identified no high-quality published economic evaluations of tagging Through applying the EMMIE framework this review highlighted the complexity involved in security tagging in retail environments, whereby different kinds of tags are expected to reduce theft through different casual mechanisms which are dependent on a distinctive configuration of conditions Based on the available evidence it is difficult to determine the effectiveness of tags as a theft reduction measure, albeit there is suggestive evidence that more visible tags are associated with greater reductions in theft than less visible tags

Multivariate analysis of energy dispersive X-ray diffraction data for the detection of illicit drugs in border control

Abstract: A system using energy dispersive X-ray diffraction has been tested to detect the presence of illicit drugs concealed within parcels typical of those which are imported into the UK via postal and courier services. The system was used to record diffraction data from calibration samples of diamorphine (heroin) and common cutting agents and a partial least squares regression model was established between diamorphine concentration and diffraction spectra. Parcels containing various crystalline and amorphous materials, including diamorphine, were then scanned to obtain multiple localised diffraction spectra and to form a hyperspectral image. The calibration model was used for the prediction of diamorphine concentration throughout the volume of parcels and enabled the presence and location of diamorphine to be determined from the visual inspection of concentration maps. This research demonstrates for the first time the potential of an EDXRD system to generate continuous hyperspectral images of real parcels from volume scanning in security applications and introduces the opportunity to explore hyperspectral image analysis in chemical and material identification. However, more work must be done to make the system ready for implementation in border control operations by bringing down the procedure time to operational requirements and by proving the system’s portability.

Personal security alarms for the prevention of assaults against healthcare staff

Abstract: Personal security alarms have been used to try to reduce violence against healthcare staff, some of whose members face relatively high risks of assault. This systematic review focused on the effect of alarms in reducing the incidence and/or severity of assaults. Electronic databases, including Cochrane Library, Ovid MEDLINE(R); CINAHL Plus (EBSCO); PubMed; PsycINFO (OvidSP) PsycEXTRA; Applied Social Sciences Index and Abstracts (ProQuest) (1987 to current); Criminal Justice Abstracts (EBSCOhost); Psychology and Behavioural Science Collection (EBSCOhost); Social Policy and Practice (OvidSP) Sociological Abstracts; ProQuest theses and dissertations, were searched. Study designs eligible for inclusion were randomised controlled trials, interrupted time series and controlled before-after studies that assessed the impact of personal security alarms on assaults. Searches were undertaken for studies of healthcare staff in all settings (i.e. including staff working in confined spaces such as hospitals and also field personnel such as community health workers). Workplace violence between colleagues (lateral violence and bullying) and other uses of personal alarms (e.g. fall alarms for the elderly, domestic violence prevention) were excluded. Search results were screened by title, abstracts and keywords for possible inclusion. Full text reports for all potentially relevant studies were obtained and independently assessed for final inclusion. The primary outcome was physical assaults (recorded or self-reported). Secondary outcomes included increased confidence or self-efficacy in violence prevention (recorded or self-reported). No studies were found that met all inclusion criteria. Four reported associations of personal alarms (and other variables) with risks of assault in healthcare settings. These were described narratively. Healthcare workers in emergency departments, psychiatric units and geriatric facilities face much higher risks of assault than those in other healthcare settings. Alarm systems vary widely. Alarm systems form one of a range of measures, which may interact with one another, that are used to reduce the risks of assault. Given this complexity and diversity, prior to field trials EMMIE orientated efficacy trials are recommended to try to establish whether alarms can be introduced and operated in ways that can contribute to reducing assaults in specific high-risk settings. In relation to findings relating to any given intervention, EMMIE refers to effects produced, mechanisms activated to produce the effects, moderators or contexts relevant to the activation of mechanisms, implementation issues that arise, and economic costs and benefits.

Retraction Note to: Investigative advising: a job for Bayes

Abstract: Bayesian approaches to police decision support offer an improvement upon more commonly used statistical approaches. Common approaches to case decision support often involve using frequencies from cases similar to the case under consideration to come to an isolated likelihood that a given suspect either a) committed the crime or b) has a given characteristic or set of characteristics. The Bayesian approach, in contrast, offers formally contextualized estimates and utilizes the formal logic desired by investigators. Bayes’ theorem incorporates the isolated likelihood as one element of a three-part equation, the other parts being 1) what was known generally about the variables in the case prior to the case occurring (the scientific-theoretical priors) and 2) the relevant base rate information that contextualizes the evidence obtained (the event context). These elements are precisely the domain of decision support specialists (investigative advisers), and the Bayesian paradigm is uniquely apt for combining them into contextualized estimates for decision support. By formally combining the relevant knowledge, context, and likelihood, Bayes’ theorem can improve the logic, accuracy, and relevance of decision support statements.