Predictive Crime Mapping: Arbitrary Grids or Street Networks?

Objectives

Decades of empirical research demonstrate that crime is concentrated at a range of spatial scales, including street segments. Further, the degree of clustering at particular geographic units remains noticeably stable and consistent; a finding that Weisburd (Criminology 53:133–157, 2015) has recently termed the ‘law of crime concentration at places’. Such findings suggest that the future locations of crime should—to some extent at least—be predictable. To date, methods of forecasting where crime is most likely to next occur have focused either on area-level or grid-based predictions. No studies of which we are aware have developed and tested the accuracy of methods for predicting the future risk of crime at the street segment level. This is surprising given that it is at this level of place that many crimes are committed and policing resources are deployed.

Methods

Using data for property crimes for a large UK metropolitan police force area, we introduce and calibrate a network-based version of prospective crime mapping [e.g. Bowers et al. (Br J Criminol 44:641–658, 2004)], and compare its performance against grid-based alternatives. We also examine how measures of predictive accuracy can be translated to the network context, and show how differences in performance between the two cases can be quantified and tested.

Results

Findings demonstrate that the calibrated network-based model substantially outperforms a grid-based alternative in terms of predictive accuracy, with, for example, approximately 20 % more crime identified at a coverage level of 5 %. The improvement in accuracy is highly statistically significant at all coverage levels tested (from 1 to 10 %).

Conclusions

This study suggests that, for property crime at least, network-based methods of crime forecasting are likely to outperform grid-based alternatives, and hence should be used in operational policing. More sophisticated variations of the model tested are possible and should be developed and tested in future research.

     

Isolating Adult Psychological Correlates of Witnessing Parental Violence: Findings from a Predominantly Latina Sample

This study examined the relationship between childhood exposure to parental violence and adult psychological functioning in a sample of predominantly Mexican American participants. Questionnaires assessing childhood maltreatment, family environment, and current psychological symptomatology were completed by 142 female undergraduates. Findings revealed that witnessing parental violence in childhood was associated with depressive symptoms, low self-esteem, and trauma symptoms in adulthood, even after controlling for child physical and sexual abuse. However, in subsequent analyses, also controlling for levels of nonphysical family conflict, previous associations between exposure to parental violence and adult symptomatology were reduced, such that trauma-related symptoms remained the sole outcome still predicted by a history of witnessing parental violence. Implications of these findings, issues related to the use of statistical control procedures in abuse effects research, and directions for future investigation are discussed.     

Type and extent of child abuse as predictors of adult functioning

Child abuse is associated with a variety of difficulties later in life. However, it is unclear to what extent these outcomes are related to the type and combinations of abuse (i.e., sexual versus physical) rather than the variable characteristics within each type. Information regarding child abuse histories as well as current functioning was gathered from a community sample of 259 working women. Incest and severe physical abuse were each associated with similar symptoms, with people who were more severely abused showing worse outcomes. Those women who were both physically and sexually abused had less favorable outcomes than those abused in only one manner. The effects of abuse could not be understood without taking combinations of different types and severities into account. The implications of the similarities of the outcomes of severe sexual and physical abuse were discussed.     

Judicial Decisions and Policy

This symposium debates the impact of High Court decisions by questioning whether the High Court has the constitutional and legislative authority (and possibly the moral right) to decide policy issues and determine the rights of citizens. Arguments on the role of the High Court vary from views that the High Court provides a sphere in which political interests may be lobbied to notions that its role is solely to interpret the Australian Constitution. However, what occurs when the political aspirations of government are in conflict with the decisions of the High Court? Should the High Court adapt judicial decisions to changing social views, or consider the implications of their decisions on the executive and legislature? What is the constitutional role of the High Court? These questions are explored in detail in the following articles.     

Secured Financing of Intellectual Property Assets and the Reform of English Personal Property Security Law

The past three decades have seen a decline in traditional industriesin the United Kingdom and there has been a relative declinein the value of physical assets to the UK economy. At the sametime, the value of intangible assets seen in intellectual propertyrights have increased considerably. As such, IP rights representimportant assets for companies and often comprise the foundationfor market dominance and continued profitability. There is astructural uncertainty in the law relating to the use of IPas collateral for the purpose of raising debt finance and thismay impact upon the survival of firms with high ratios of intangibleto tangible assets. This article considers the proper goalsfor an effective credit and security regime in IP. It examinesthe significance of the availability of collateral to the lendingdecision and also considers whether the reluctance to maximisethe use of IP as security reflects inherent difficulties whicharise out of the nature of IP as economic assets. This has implicationsfor the reform of English personal property security law andthe development of bright line priority rules associated withArticle 9 of the US Uniform Commercial Code which is often citedas a model for reform of English law.     

A further study to investigate the detection and enhancement of latent fingerprints using visible absorption and luminescence chemical imaging

This study investigated the application of chemical imaging to the detection of latent fingerprints using the Condor macroscopic chemical imaging system (ChemImage Corp., Pittsburgh, USA). Methods were developed and optimised for the visualisation of untreated latent fingerprints and fingerprints processed with DFO, ninhydrin, cyanoacrylate, and cyanoacrylate plus rhodamine 6G stain. The results obtained with chemical imaging were compared to the detection achieved using conventional imaging techniques. The Condor significantly improved the detection of many prints, especially those that might be considered poor quality or borderline prints. Prints on newspaper treated with ninhydrin and DFO, and prints on white and yellow paper treated with ninhydrin, benefited the most from chemical imaging detection. In many cases, fingerprints undetectable using conventional imaging techniques could be visualised with chemical imaging. Ridge detail from untreated prints on yellow paper was also detected using the Condor. When prints of high quality were examined, both detection techniques produced quality results. The results of this project demonstrate that chemical imaging offers advantages over conventional visualisation techniques when examining latent fingerprints, especially those that would be considered difficult, such as weak prints or prints on surfaces that produce highly luminescent backgrounds. Standard testing procedures for the detection and enhancement of fingerprints by chemical imaging are presented and discussed.