The Efficacy of Ideographic Models for Geographical Offender Profiling

Objectives

Current ‘geographical offender profiling’ methods that predict an offender’s base location from information about where he commits his crimes have been limited by being based on aggregate distributions across a number of offenders, restricting their responsiveness to variations between individuals as well as the possibility of axially distorted distributions. The efficacy of five ideographic models (derived only from individual crime series) was therefore tested.

Methods

A dataset of 63 burglary series from the UK was analysed using five different ideographic models to make predictions of the likely location of an offenders home/base: (1) a Gaussian-based density analysis (kernel density estimation); (2) a regression-based analysis; (3) an application of the ‘Circle Hypothesis’; (4) a mixed Gaussian method; and (5) a Minimum Spanning Tree (MST) analysis. These tests were carried out by incorporating the models into a new version of the widely utilised Dragnet geographical profiling system DragNetP. The efficacy of the models was determined using both distance and area measures.

Results

Results were compared between the different models and with previously reported findings employing nomothetic algorithms, Bayesian approaches and human judges. Overall the ideographic models performed better than alternate strategies and human judges. Each model was optimal for some crime series, no one model producing the best results for all series.

Conclusions

Although restricted to one limited sample the current study does show that these offenders vary considerably in the spatial distribution of offence location choice. This points to important differences between offenders in the morphology of their crime location choice. Mathematical models therefore need to take this into account. Such models, which do not draw on any aggregate distributions, will improve geographically based investigative decision support systems.     

Identification of impurities and statistical classification of methamphetamine tablets (Ya-Ba) seized in Thailand

Impurity profiles of methamphetamine tablets seized in Thailand have been investigated. The samples are extracted with small amounts of ethyl acetate under alkaline condition and the extracts are analyzed by capillary gas chromatography. Nine compounds (1,2-dimethyl-3-phenylaziridine, ephedrine, methylephedrine, N-formylmethamphetamine, N-acetylmethamphetamine, N-formylephedrine, N-acetylephedrine, N,O-diacetylephedrie, methamphetamine dimer) are identified as impurities in methamphetamine tablet. Caffeine and ethyl vanillin are also detected as diluents and/or adulterants, and acetylcodeine monoacetylmorphine and diacetylmorphine are contained in many samples. In addition, trans-3,4-dimethyl-5-phenyl-2-oxazolidone is newly found as an impurity. For characterization and comparison of methamphetamine tablet exhibits, intensely and commonly detectable nine peaks are selected as the factor for multivariate analysis. The procedures reported here permit classification of 250 analyzed exhibits into five groups and characterization of classified groups.     

Reviews

Orlando Figes, Peasant Russia, Civil War: The Volga Countryside in Revolution, 1917–1921. Oxford: Clarendon Press, 1989, xx + 401 pp., £40.00.

Hugh Macdonald, The Soviet Challenge and the Structure of European Security. Aldershot: Edward Elgar, 1990, ix + 318 pp., £38.50.

Jonathan Eyal, ed. The Warsaw Pact and the Balkans: Moscow's Southern Flank. London: Macmillan Press, 1989, xvi + 246 pp., £35.00.

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Terry L. Thompson, Ideology and Policy: The Political Uses of Doctrine in the Soviet Union. London: Westview Press, Westview Special Studies on the Soviet Union and Eastern Europe, 1989, viii + 220 pp., $28.95 p/b.

Mary Buckley, Women and Ideology in the Soviet Union. London: Harvester Wheatsheaf, 1989, 266 pp., £9.95 p/b.

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Jerzy Tomaszewski, The Socialist Regimes of East Central Europe: Their Establishment and Consolidation 1944–67, Trans. Jolanta Krauze. London: Routledge, 1989, 305 pp., £40.00.

Paul G. Lewis, Political Authority and Party Secretaries in Poland 1975–1986. Cambridge: Cambridge University Press, 1989, xix + 340 pp., £35.00.

Leonard J. Cohen, The Socialist Pyramid: Elites and Power in Yugoslavia. Oakville, TX: Mosaic Press, 1989, 499 pp., $29.95 h/b, $19.95 p/b.

Diane P. Koenker & William G. Rosenberg, Strikes and Revolution in Russia, 1917. Princeton, NJ: Princeton University Press, 1989, xix + 393 pp., $39.50.     

Group selection of service efforts and accomplishments indicators for colleges

In this study, a set of key Service Efforts and Accomplishments (SEA) indicators was determined for higher-education external reports. Personal interviews were conducted with presidents and administrators from 28 colleges to determine their preferences for and the usefulness of performance indicators. Participants’ perceptions were analyzed using the analytic hierarchy process. In addition to determining indicators, the study discovered an unexpectedly high correlation between the key indicators selected by private and public institutions.     

Broadening the approach to youth violence prevention through public health

Violence is a critical cause of death and nonfatal injuries among youth, and even those who witness violence can suffer serious health and mental health consequences. This highlights the need for prevention programs and policies aimed at reducing risks, promoting prosocial behavior, strengthening families, and creating communities in which youth are safe from violence. The Centers for Disease Control and Prevention's Injury Center is developing a National Public Health Strategy to Prevent Youth Violence. The strategy will establish a full application of the public health approach, ranging from research to practice. It also spotlights what is working, as a way to mobilize community leaders in supporting evidence-based initiatives. With the empirical guidance of articles such as those in this special issue, a shared strategy to prevent youth violence will help focus efforts and resources on solutions that show the most promise, and ensure that American communities undertake more comprehensive and coordinated prevention efforts to protect our nation's youth.     

State mortgage foreclosure policies and lender interventions: Impacts on borrower behavior in default

Due to the rise in foreclosure filings, policymakers are increasingly concerned with helping families in financial distress keep their homes. This paper tests the extent to which distressed mortgage borrowers benefit from three types of state foreclosure polices: (1) judicial foreclosure proceedings, (2) statutory rights of redemption, and (3) statewide foreclosure‐prevention initiatives. Based on an analysis of borrowers in default who reside in 22 cross‐state metropolitan statistical area pairs, state policies generally have weak effects. Both judicial foreclosure proceedings and foreclosure prevention initiatives are associated with modest increases in loan modification rates. Using a matching procedure, a lender's letter promoting mortgage default counseling was associated with increases in loan modifications, decreases in loan cures, and decreases in foreclosure starts. The effects of the letter were also stronger in states with judicial proceedings. © 2011 by the Association for Public Policy Analysis and Management.