Tom Pakkanen, Jukka Sirén, Angelo Zappalà, Patrick Jern, Dario Bosco, Andrea Berti and Pekka Santtila
Crime linkage analysis (CLA) can be applied in the police investigation-phase to sift through a database to find behaviorally similar cases to the one under investigation and in…
Abstract
Purpose
Crime linkage analysis (CLA) can be applied in the police investigation-phase to sift through a database to find behaviorally similar cases to the one under investigation and in the trial-phase to try to prove that the perpetrator of two or more offences is the same, by showing similarity and distinctiveness in the offences. Lately, research has moved toward more naturalistic settings, analyzing data sets that are as similar to actual crime databases as possible. One such step has been to include one-off offences in the data sets, but this has not yet been done with homicide. The purpose of this paper is to investigate how linking accuracy of serial homicide is affected as a function of added hard-to-solve one-off offences.
Design/methodology/approach
A sample (N = 117–1160) of Italian serial homicides (n = 116) and hard-to-solve one-off homicides (n = 1–1044, simulated from 45 cases) was analyzed using a Bayesian approach to identify series membership, and a case by case comparison of similarity using Jaccard’s coefficient. Linking accuracy was evaluated using receiver operating characteristics and by examining the sensitivity and specificity of the model.
Findings
After an initial dip in linking accuracy (as measured by the AUC), the accuracy increased as more one-offs were added to the data. While adding one-offs made it easier to identify correct series (increased sensitivity), there was an increase in false positives (decreased specificity) in the linkage decisions. When rank ordering cases according to similarity, linkage accuracy was affected negatively as a function of added non-serial cases.
Practical implications
While using a more natural data set, in terms of adding a significant portion of non-serial homicides into the mix, does introduce error into the linkage decision, the authors conclude that taken overall, the findings still support the validity of CLA in practice.
Originality/value
This is the first crime linkage study on homicide to investigate how linking accuracy is affected as a function of non-serial cases being introduced into the data.
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Keywords
Tom Pakkanen, Angelo Zappalà, Dario Bosco, Andrea Berti and Pekka Santtila
The purpose of this paper is to explore the differences (if any) between serial and hard-to-solve one-off homicides, and to determine if it is possible to distinguish the two…
Abstract
Purpose
The purpose of this paper is to explore the differences (if any) between serial and hard-to-solve one-off homicides, and to determine if it is possible to distinguish the two types of homicides based on offence behaviours and victim characteristics.
Design/methodology/approach
A sample of 116 Italian serial homicides was compared to 45 hard-to-solve one-off homicides. Hard-to-solve one-off homicides were defined as having at least 72 hours pass between when the offence came to the knowledge of the police and when the offender was caught. Logistic regression was used to predict whether a killing was part of a series or a one-off offence.
Findings
The serial killers targeted more strangers and prostitutes, displayed a higher level of forensic awareness both before and after the killing, and had more often an apparent sexual element in their offence. Conversely, the one-off homicides were found to include more traits indicative of impulsive and expressive behaviour. The model demonstrated a good ability (AUC=0.88) to predict whether a homicide belonged to the serial or one-off category.
Research limitations/implications
The findings should be replicated using local homicide data to maximise the validity of the model in countries outside of Italy.
Practical implications
Being able to distinguish between serial and one-off homicides based on information available at a new crime scene could be practically useful for homicide investigators managing finite resources.
Originality/value
Studies comparing serial homicides to one-off homicides are scarce, and there are no studies explicitly trying to predict whether a homicide is an isolated case or part of a series.
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Maria Ioannou and Laura Hammond
Homicidal behaviour is influenced by a complex interaction of behavioural, situational and environmental factors that raise many challenging psychological questions. A large and…
Abstract
Purpose
Homicidal behaviour is influenced by a complex interaction of behavioural, situational and environmental factors that raise many challenging psychological questions. A large and continually growing body of research has explored the crime of homicide, its epidemiology, victims and perpetrators. The area is developing rapidly, opening up new avenues of study. The paper aims to discuss these issues.
Design/methodology/approach
This special issue of the Journal of Criminal Psychology brings together an exciting array of papers on homicidal behaviour, examining a wide range of issues including juvenile homicide perpetrators, school shootings, child homicide, homicide-suicide and differences in offence behaviours and victim characteristics between hard-to-solve one-off homicides and serial homicides.
Findings
The range of papers included in this special edition cover a wide range of aspects of homicidal behaviour, reflecting the importance of – and the need for – applied research moving away from examining general homicide to specialised research focusing on subtypes of homicide and subgroups of homicide offenders. A research agenda is proposed.
Originality/value
This editorial gives an introduction to the themes explored in this special issue and provides an overview of the selected papers.
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The purpose of this study is to present a comprehensive review of the fundamental concepts and terminologies pertaining to different types of aluminium metal matrix composites…
Abstract
Purpose
The purpose of this study is to present a comprehensive review of the fundamental concepts and terminologies pertaining to different types of aluminium metal matrix composites, their joining techniques and challenges, friction stir welding (FSW) process, post-welding characterizations and basic control theory of FSW, followed by the discussions on the research reports in these areas.
Design/methodology/approach
Joining of aluminium metal matrix composites (Al-MMC) poses many challenges. These materials have their demanding applications in versatile domains, and hence it is essential to understand their weldability and material characteristics. FSW is a feasible choice for joining of Al-MMC over the fusion welding because of the formation of narrow heat affected zone and minimizing the formation of intermetallic compounds at weld interface. The goal in FSW is to generate enough thermal energy by friction between the workpiece and rotating tool. Heat energy is generated by mechanical interaction because of the difference in velocity between the workpiece and rotating tool. In the present work, a detailed survey is done on the above topics and an organised conceptual context is presented. A complete discussion on significance of FSW process parameters, control schemes, parameter optimization and weld quality monitoring are presented, along with the analysis on relation between the interdependent parameters.
Findings
Results from the study present the research gaps in the FSW studies for joining of the aluminium-based metal matrix composites, and they highlight further scope of studies pertaining to this domain.
Originality/value
It is observed that the survey done on FSW of Al-MMCs and their control theory give an insight into the fundamental concepts pertaining to this research area to enhance interdisciplinary technology exploration.
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Coosje Hammink, Nienke Moor and Masi Mohammadi
This systematic literature review focusses on original research that examines the effect of persuasive architectural interventions on stimulating health behaviour. This paper…
Abstract
Purpose
This systematic literature review focusses on original research that examines the effect of persuasive architectural interventions on stimulating health behaviour. This paper gives an overview of the empirical evidence and aims to examine the evidence for health behaviour change through architectural interventions and the underlying theoretical pathways and mechanisms using social cognitive theory.
Design/methodology/approach
This paper reviewed 40 peer-reviewed articles found through Scopus, Google Scholar, Web of Science, PubMed and a supplementary hand search and examined for effect, type of interventions, type of behaviour and underlying mechanisms using social cognitive theory.
Findings
This review shows that architectural interventions can stimulate healthy behaviour. However, much of the research focusses on specific health behaviours (physical activity), in specific target groups (children or older adults) and with specific types of interventions (supplying provisions). Furthermore, the effect of the physical environment on cognitive factors should be taken into consideration.
Research limitations/implications
Hardly any research on smart architectural interventions for health behaviour change exists, but combining insights from product design and built environment has the potential to impact designing for health behaviour change.
Originality/value
Stimulating certain types of health behaviour can positively contribute to health goals and has been the focus of many health promotion practitioners over the years. The focus of health promotion interventions has primarily been on social and psychological factors. However, current research shows the importance of the physical environment as an influence on health behaviour. Potentially, with the use of smart technology, this effect could be enhanced.