Predicting offender home location in urban burglary series

Residential location of a criminal can be predicted statistically [M. Laukkanen, P. Santtila, Predicting the home location of a serial commercial robber, Forensic Sci. Int. 157 (2006) 71-82]. Examined were: accuracy of the technique for urban burglary series, correlations between way of committing burglary and distance and use of those correlations in enhancing prediction accuracy. Data: 78 residential burglary series from Greater Helsinki area, Finland. Series for which the home location prediction was made was never part of the predicting model. Distances between home and crime-site were short (Mdn 3.88km; IQR=1.16-10.10km). Search area of a perpetrator could be limited to 1.95% (Mdn, IQR=0.64-18.70%) of the total study area. For series which conformed to Circle Hypothesis (45%), search area was 0.84% (Mdn, IQR=0.51-2.34%). Correlations between crime features and distance were found to enhance accuracy when features of series hinted short distance: sub-model limited search area to 0.19% (Mdn, IQR=0.07-0.65%).     

Even criminals take a holiday: Instrumental and expressive crimes on major and minor holidays

Based on routine activity (RA) theory, the authors hypothesized that crime rates would vary with both the type of crime and the type of holiday, with violent crimes occurring more frequently and property crimes occurring less frequently on major holidays that brought families together in the home. It was also hypothesized that minor holidays would have little or no impact on crime rates. These hypotheses were tested by subjecting data on calls for service in Minneapolis, Minnesota, in 1985, 1987, and 1988 to time series analyses. After controlling for time of day, day of week, month, four weather variables, the first day of the month, linear trend, and autocorrelation, regression analyses indicated that both violent and property crimes were significantly related to major (or legal) holidays, whereas neither type of crime was more likely to occur on minor holidays. Crimes of expressive violence were significantly more prevalent on major holidays, whereas property crimes were less frequent on those days.     

Behavioural case linkage with solved and unsolved crimes

Offender behaviour is used to distinguish between crimes committed by the same person (linked crimes) and crimes committed by different people (unlinked crimes) through behavioural case linkage. There is growing evidence to support the use of behavioural case linkage by investigative organisations such as the police, but this research is typically limited to samples of solved crime that do not reflect how this procedure is used in real life. The current paper extends previous research by testing the potential for behavioural case linkage in a sample containing both solved and unsolved crimes. Discrimination accuracy is examined across crime categories (e.g. a crime pair containing a car theft and a residential burglary), across crime types (e.g. a crime pair containing a residential burglary and a commercial burglary), and within crime types (e.g. a crime pair containing two residential burglaries) using the number of kilometres (intercrime distance) and the number of days (temporal proximity) between offences to distinguish between linked and unlinked crimes. The intercrime distance and/or the temporal proximity were able to achieve statistically significant levels of discrimination accuracy across crime categories, across crime types, and within crime types as measured by Receiver Operating Characteristic (ROC) analysis. This suggests that behavioural case linkage can be used to assist the investigation, detection and prosecution of prolific and versatile serial offenders.     

On the Complexity and Accuracy of Geographic Profiling Strategies

Geographic profilers have access to a repertoire of strategies for predicting a serial offenders home location. These strategies range in complexity—some involve more calculations to implement than others—and the assumption often made is that more complex strategies will outperform simpler strategies. In the present study, we tested the relationship between the complexity and accuracy of 11 strategies. Data were crime site and home locations of 16 UK residential burglars who had committed 10 or more crimes each. The results indicated that strategy complexity was not positively related to accuracy. This was also found to be the case across tasks that ranged in complexity (where complexity was determined by the number of crimes used to make a prediction). Implications for police policies and procedures, as well as our understanding of human decision-making, are discussed.To whom correspondence should be addressed. Phone: +1-709-737-3101; E-mail: bsnook@play.psych.mun.ca     

Narratives of criminal action and forensic psychology

Purpose. In commenting on Youngs and Canter's (2011) study, Ward (2011) raises concerns about offenders’ personal narratives and their link to self‐concepts and identity. His comments relate to explorations of personal life stories rather than the narratives of actual crimes that are the focus of Youngs and Canter's (2011) study. The elaboration of this different focus helps to allay many of Ward's (2011) concerns and reveals further possibilities for developing the narrative approach within forensic psychology. Methods. The focus on offenders’ accounts of a particular crime allows the development of a standard pro forma, the Narrative Role Questionnaire (NRQ), which deals with the roles a person thinks they played when committing a crime. These roles act as a summary of the criminal's offence narrative. Multivariate analysis of the NRQ clarifies the specific narrative themes explored by Youngs and Canter (2011) . Results. The examination of the components of the NRQ indicates that offence narratives encapsulate many psychological processes including thinking styles, self‐concepts, and affective components. This allows the four narrative themes identified by Youngs and Canter to provide the basis for rich hypotheses about the interaction between the dynamics of personal stories and identity. The four narratives of criminal action also offer a foundation for understanding the particular, detailed styles of offending action and the immediate, direct processes that act to instigate and shape these. Conclusion. These developments in our understanding of offence narratives generate fruitful research questions that bridge the concerns of investigative and correctional applications of narrative theory.     

A Test of Case Linkage Principles with Solved and Unsolved Serial Rapes

Case linkage involves identifying crime series on the basis of behavioral similarity and distinctiveness. Research regarding the behavioral consistency of serial rapists has accumulated; however, it has its limitations. One of these limitations is that convicted or solved crime series are exclusively sampled whereas, in practice, case linkage is applied to unsolved crimes. Further, concerns have been raised that previous studies might have reported inflated estimates of case linkage effectiveness due to sampling series that were first identified based on similar modus operandi (MO), thereby overestimating the degree of consistency and distinctiveness that would exist in naturalistic settings. We present the first study to overcome these limitations; we tested the assumptions of case linkage with a sample containing 1) offenses that remain unsolved, and 2) crime series that were first identified as possible series through DNA matches, rather than similar MO. Twenty-two series consisting of 119 rapes from South Africa were used to create a dataset of 7021 crime pairs. Comparisons of crime pairs that were linked using MO vs. DNA revealed significant, but small differences in behavioral similarity with MO-linked crimes being characterized by greater similarity. When combining these two types of crimes together, linked pairs (those committed by the same serial offender) were significantly more similar in MO behavior than unlinked pairs (those committed by two different offenders) and could be differentiated from them. These findings support the underlying assumptions of case linkage. Additional factors thought to impact on linkage accuracy were also investigated.     

Sexual offenders’ treatment experience: a qualitative and quantitative investigation

Abstract

This research investigates the where and when of sexual assaults to determine what types of sexual crimes are committed at different time and place classifications. Exhaustive CHAID (chi-squared automatic interaction detection) analyses are conducted, examining factors associated with crimes that were committed indoors or outdoors, in private or public places, during the day or at night, and during the week or on the weekend. These methods are applied to a sample of 361 sexual crime events committed by 72 serial sex offenders. The results are strikingly different dependent on which spatial or temporal aspect of the crime is examined, which implies the complexity of sexual crime events and their situational components. This research brings to light possible policy implications with respect to situational crime prevention.     

THE NEGLECTED SITUATION: A CROSSNATIONAL STUDY OF THE SITUATIONAL CHARACTERISTICS OF CRIME*

Although it is generally recognized in the social sciences that the “situation” is indispensable for understanding behavior, thus far criminologists have not devoted systematic attention to situational analysis. This paper contributes to the development of a situational perspective on crime by defining the concept of situation, developing four hypotheses about the situational characteristics of selected personal contact crimes, and then testing those hypotheses using victimization survey data from the United States and Venezuela. The research shows that coercive crimes are less situationally clustered than noncoercive crimes and that instrumental crimes are more situationally clustered than character crimes. Despite tremendous differences in crime rates for the two countries, substantial similarity is found in situational crime patterns. The implications of the research for criminological theory are discussed.     

Sequential angulation,spatial dispersion and consistency of distance attack patterns from home in serial murder,rape and burglary

Abstract

Three related measures of spatial movement (sequential angulation, spatial dispersion and consistency of distance in attack target) were compared across three serial offence types: serial homicide (n=35), serial rape (n=41) and serial burglary (n=30). In each case, each offender had committed at least five offences. “Spatial dispersion”, defined as the extent to which an offender distributes his offences across either a focused or relatively more evenly distributed area, revealed that burglary was less evenly distributed (i.e. more focused) than rape and murder. “Sequential angulation”, defined as the degree of rotational movement around the home of the offender from one offence to the next, revealed that serial murderers have higher angulation scores than do rapists who, in turn, have higher angulation scores than burglars. Lastly, a comparison of the offender's consistency in the relative distance travelled from home to each attack site (“consistency of distance in attack target”) was relatively similar across the three groups. This was despite the comparison of different serial offence types from disparate geographical areas. The supposition that differences in dispersion and sequential angulation scores across crime types are related to the perceived risk of the crime has been confirmed. The specificity and the mobility of the targets are also discussed.     

The Law of Crime Concentration: An Application and Recommendations for Future Research

Objective

We address four outstanding empirical questions related to the “law of crime concentration” (Weisburd in Criminology 53:133–157, 2015): (1) Is the spatial concentration of crime stable over time? (2) Do the same places consistently rank among those with the highest crime counts? (3) How much crime concentration would be observed if crimes were distributed randomly over place? (4) To what degree does the spatial concentration of crime depend on places that are crime free?

Methods

The data are annual counts of violent and property crimes in St. Louis between 2000 and 2014. Temporal stability in the spatial inequality of crime is measured by computing the fraction of crimes that occur in the 5% of street segments with the highest crime frequencies each year. The spatial mobility of crime is measured by computing the number of years each street segment appears in the top 5% of street segments. Poisson simulations are used to estimate the fraction of crimes that could appear in the top 5% of street segments on the basis of chance alone. The impact of crime-free locales on the spatial concentration of crime is evaluated by comparing results from analyses that include and exclude crime-free street segments from the crime distributions.

Results

The concentration of crime is highly unequal and stable over time. The specific street segments with the highest crime frequencies, however, change over time. Nontrivial fractions of street segments may appear among the 5% with the highest crime frequencies on the basis of chance. Spatial concentration of crime is reduced when crime-free street segments are excluded from the crime distributions.

Conclusions

The law of crime concentration is not a measurement artifact. Its substantive significance, however, should be assessed in future longitudinal research that replicates the current study across diverse social settings.

     

Correlates of distance to crime in Mexico City

This study examined the correlates of distance to crime in a sample of 412 prison inmates in the Mexico City Metropolitan Area. The study focused on crimes of theft and included a spatial analysis of the crime scene and the place of residence of the prison inmates. The data show a high clustering of criminals in a few neighbourhoods surrounding the old downtown area. Also, 38.8% of the sampled criminals committed their crimes in the same neighbourhood where they lived. Regression analysis revealed two independent and positive correlations of distance to crime: the monetary gain of the crime and if the prison inmates' intimate partner was also in jail. These findings suggest that, aside from the monetary rationale in the distance to crime function, the neighbourhood and family contexts deserve further research for a better understanding of criminal behaviour in Mexico.     

Addressing problems with traditional crime linking methods using receiver operating characteristic analysis

Purpose. Through an examination of serial rape data, the current article presents arguments supporting the use of receiver operating characteristic (ROC) analysis over traditional methods in addressing challenges that arise when attempting to link serial crimes. Primarily, these arguments centre on the fact that traditional linking methods do not take into account how linking accuracy will vary as a function of the threshold used for determining when two crimes are similar enough to be considered linked. Methods. Considered for analysis were 27 crime scene behaviours exhibited in 126 rapes, which were committed by 42 perpetrators. Similarity scores were derived for every possible crime pair in the sample. These measures of similarity were then subjected to ROC analysis in order to (1) determine threshold‐independent measures of linking accuracy and (2) set appropriate decision thresholds for linking purposes. Results. By providing a measure of linking accuracy that is not biased by threshold placement, the analysis confirmed that it is possible to link crimes at a level that significantly exceeds chance (AUC = .75). The use of ROC analysis also allowed for the identification of decision thresholds that resulted in the desired balance between various linking outcomes (e.g. hits and false alarms). Conclusions. ROC analysis is exclusive in its ability to circumvent the limitations of threshold‐specific results yielded from traditional approaches to linkage analysis. Moreover, results of the current analysis provide a basis for challenging common assumptions underlying the linking task.     

Consistency in crime site selection: An investigation of crime sites used by serial sex offenders across crime series

PurposeKnowing sites used by serial sex offenders to commit their crimes is highly beneficial for criminal investigations. However, environmental choices of serial sex offenders remain unclear to this date. Considering the challenges these offenders pose to law enforcement, the study aims to identify sites serial sex offenders use to encounter and release their victims and investigate their stability across crime series.MethodsThe study uses latent class analysis (LCA) to identify victim encounter and release sites used by 72 serial sex offenders having committed 361 sex offenses. Additional LCA are performed to investigate the stability of these offense environments across offenders' crimes series.ResultsDistinct profiles of crime sites that are recurrent across crime series are found, suggesting that serial sex offenders present a limited diversity of victim encounter and victim release sites. Encounter sites representative of longer crime series are also identified. Specifically, the use of sites known to "attract" potential victims decreases over series and offenders become more risk-taking in regard of sites used to encounter their victims.ConclusionsThe study identifies patterns of site- selection for the victim encounter and release in cases of serial crimes. Implications for crime linkage and police investigations strategies are discussed.     

Are DNA data a valid source to study the spatial behavior of unknown offenders?

Studying the spatial behaviour of unknown offenders (i.e. undetected offenders) is difficult, because police recorded crime data do not contain information about these offenders. Recently, forensic DNA data has been used to study unknown offenders. However, DNA data are only a subset of the crimes committed by unknown offenders stored in police recorded crime data. To establish the suitability of DNA data for studying the spatial offending behaviour of unknown offenders, we examine the concentration and spatial similarity of detected but unsolved crimes in police recorded crime data (N?=?181,483) and DNA data (N?=?1913) over 27 Belgian judicial districts for four crime types. We established spatial similarity for certain crime types (in some districts). This offers opportunities for DNA data to be used to study unknown offenders' spatial offending behaviour. Implications for theory and research are discussed.     

Examining the relationship between routine activities theory and social disorganization: An analysis of property crime victimization

A property crime victimization survey was conducted of households in both high and tow crime neighborhoods in one southern city. A response rate of 68.5% was obtained. The study tested the premises of both the routine activities and social disorganization theories as they contribute to the likelihood of property crime victimization at the individual level. It was found that routine activities theory explained 28% of the property crime variance in the socially disorganized area (high crime) while only explaining 11% of the same variance in the low crime area. Separate measurements were used to establish the level of social disorganization in the two geographical areas. The beta coefficients reveal that in the high crime area, those most likely to be property crime victims are white, single homeowners who are not at home from 6 p.m. to 11 p.m., who have relatives living in their neighborhoods, and who interact with their neighbors. These findings lend marginal support to the routine activities model.     

Urban crime trends and patterns in Ghana: The case of Accra

The study examined the broad crime trends and patterns, and the conditions under which crimes flourish, the crime incidence rates per 1,000 of population, and crime among the four police divisions of Accra, Ghana. Where crimes clustered the most and the times some crimes were committed were examined using the official police data. The study suggests that crime in Accra has been accentuated by rigid centralization of government bureaucracy, the nature of Ghana's economy, routine activities, lifestyles, and opportunities fostered by social change. Overall, the Accra Central Police Division recorded the highest volume of crimes, followed by the Nima, Kaneshie, and Kpeshie Divisions. The highest property offenses were recorded within twelve miles of the city center—the area most congested and heavily concentrated with socio-economic and routine activities. Calls for the adoption of situational crime prevention methods and strategies to reduce the incidence of crime in Accra have been made.     

The Motivation Behind Serial Sexual Homicide: Is It Sex,Power, and Control,or Anger?*

Controversy exists in the literature and society regarding what motivates serial sexual killers to commit their crimes. Hypotheses range from the seeking of sexual gratification to the achievement of power and control to the expression of anger. The authors provide theoretical, empirical, evolutionary, and physiological support for the argument that serial sexual murderers above all commit their crimes in pursuit of sadistic pleasure. The seeking of power and control over victims is believed to serve the two secondary purposes of heightening sexual arousal and ensuring victim presence for the crime. Anger is not considered a key component of these offenders' motivation due to its inhibitory physiological effect on sexual functioning. On the contrary, criminal investigations into serial sexual killings consistently reveal erotically charged crimes, with sexual motivation expressed either overtly or symbolically. Although anger may be correlated with serial sexual homicide offenders, as it is with criminal offenders in general, it is not causative. The authors further believe serial sexual murderers should be considered sex offenders. A significant proportion of them appear to have paraphilic disorders within the spectrum of sexual sadism. "sexual sadism, homicidal type" is proposed as a diagnostic subtype of sexual sadism applicable to many of these offenders, and a suggested modification of DSM criteria is presented.     

Juvenile firesetters: Crime scene actions and offender characteristics

Purpose. To investigate whether and to what extent the thematic structure of crime scene actions in arsons identified in Canter and Fritzon (1998) is replicated for juvenile firesetters and to explore whether any associations between the crime scene action themes and offender characteristics would be evident. Methods. The crime scene actions and offender characteristics of 61 male and 5 female juvenile firesetters (aged 6‐17 years) were examined. The data were drawn from a larger database originally collected and content analysed in Fritzon (1998). In total, 43 dichotomous crime scene actions, 17 offender background characteristics and offender criminal record variables had been coded. Smallest space analysis was employed to examine the configuration of crime scene action and offender characteristic variables. The associations between the crime scene actions and offender characteristics, as well as the criminal record variables, were analysed using the correlation. Results. Distinct structural themes for crime scene actions were found in juvenile firesetting, similar to those identified in Canter and Fritzon (1998). Contrary to Canter and Fritzon, only two groups of background characteristics were identified, depressed and delinquent, the latter being more common and related to an instrumental form of firesetting. The expressive form of firesetting was associated with offenders' psychopathology and female gender. The presence of a crime scene action theme was associated with the offender's age. Conclusions. The structural themes of firesetting behaviour appear to transpire early. The background characteristics of juvenile firesetters indicate that juvenile firesetting is often associated with antisocial behaviour and psychopathology, deserving, therefore, disparate prevention, intervention and investigation programmes.     

系列犯罪规律性初探

系列犯罪是同一犯罪主体（包括个体和群体）所实施的两起以上的犯罪。它有没有规律性可言？根据前人的不懈探索和我们的问卷调查，回答是肯定的。为此，应借鉴已有研究成果和开展实证研究的基础上，总结出它们的地域规律、动力定型规律、恶性转化规律以及系列犯罪过程不断自我暴露过程的规律。