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The present study aims to examine the scope and contribution of behavioural investigative advice (BIA) reports from the National Crime Agency (NCA).

The 77 BIA reports reviewed were written between 2016 and 2021. They were evaluated using Toulmin’s (1958) strategy for structuring pertinent arguments, current compliance with professional standards, the grounds and backing provided for the claims made and the potential utility of the recommendations provided.

Consistent with previous research, most of the reports involved murder and sexual offences. The BIA reports met professional standards with extremely high frequency. The 77 reports contained a total of 1,308 claims of which 99% were based on stated grounds. A warrant and/or backing was provided for 73% of the claims. Most of the claims in the BIA reports involved a behavioural evaluation of the crime scene and offender characteristics. The potential utility of the reports was judged to be 95% for informative behavioural crime scene analysis and 40% for potential new lines of enquiry.

The reports should serve as a model for the work of behavioural investigative advisers internationally.

To the best of the authors’ knowledge, this is the first study to systematically evaluate BIA reports commissioned by the NCA; it adds to previous similar studies by evaluating the largest number of BIA reports ever reviewed, and uniquely provides judgement of overall utility.

This study aims to examine the scope and contribution of Forensic Clinical Psychology (FCP) advice from the National Crime Agency (NCA) to criminal investigations in the UK to address the gap in current knowledge and research.

The 36 FCP reports reviewed were written between 2017 and 2021. They were analysed using Toulmin’s (1958) application of pertinent arguments to the evaluation process. The potential utility of the reports was analysed in terms of the advice provided.

Most of the reports involved murder and equivocal death. The reports focused primarily on understanding the offender’s psychopathology, actions, motivation and risk to self and others using a practitioner model of case study methodology. Out of the 539 claims, grounds were provided for 99% of the claims, 91% had designated modality, 62% of the claims were potentially verifiable and 57% of the claims were supported by a warrant and/or backing. Most of the reports provided either moderate or high insight into the offence/offender (92%) and potential for new leads (64%).

The advice provided relied heavily on extensive forensic clinical and investigative experience of offenders, guided by theory and research and was often performed under considerable time pressure. Flexibility, impartiality, rigour and resilience are essential prerequisites for this type of work.

To the best of the authors’ knowledge, this study is the first to systematically evaluate forensic clinical psychology reports from the NCA. It shows the pragmatic, dynamic and varied nature of FCP contributions to investigations and its potential utility.

The purpose of this paper is to identify offender typologies based on aspects of the offenders’ psychopathology and their associations with crime scene behaviours using data derived from the National Confidential Enquiry into Suicide and Safety in Mental Health concerning homicides in England and Wales committed by offenders in contact with mental health services in the year preceding the offence (n=759).

The authors used multiple correspondence analysis to investigate the interrelationships between the variables and hierarchical agglomerative clustering to identify offender typologies. Variables describing: the offenders’ mental health histories; the offenders’ mental state at the time of offence; characteristics useful for police investigations; and patterns of crime scene behaviours were included.

Results showed differences in the offenders’ histories in relation to their crime scene behaviours. Further, analyses revealed three homicide typologies: externalising, psychosis and depression.

These typologies may assist the police during homicide investigations by: furthering their understanding of the crime or likely suspect; offering insights into crime patterns; provide advice as to what an offender’s offence behaviour might signify about his/her mental health background. Findings suggest information concerning offender psychopathology may be useful for offender profiling purposes in cases of homicide offenders with schizophrenia, depression and comorbid diagnosis of personality disorder and alcohol/drug dependence.

Empirical studies with an emphasis on offender profiling have almost exclusively focussed on the inference of offender demographic characteristics. This study provides a first step in the exploration of offender psychopathology and its integration to the multivariate analysis of offence information for the purposes of investigative profiling of homicide by identifying the dominant patterns of mental illness within homicidal behaviour.

The purpose of this paper is to discuss and demonstrate “best practices” for creating quantitative behavioural investigative advice (i.e. statements to assist police with psychological and behavioural aspects of investigations) where complex statistical modelling is not available.

Using a sample of 361 serial stranger sexual offenses and a cross-validation approach, the paper demonstrates prediction of offender characteristics using base rates and using Bayes’ Theorem. The paper predicts four dichotomous offender characteristic variables, first using simple base rates, then using Bayes’ Theorem with 16 categorical crime scene variable predictors.

Both methods consistently predict better than chance. By incorporating more information, analyses based on Bayes’ Theorem (74.6 per cent accurate) predict with 11.1 per cent more accuracy overall than analyses based on base rates (63.5 per cent accurate), and provide improved advising estimates in line with best practices.

The study demonstrates how useful predictions of offender characteristics can be acquired from crime information without large (i.e. >500 cases) data sets or “trained” statistical models. Advising statements are constructed for discussion, and results are discussed in terms of the pragmatic usefulness of the methods for police investigations.

The purpose of this paper is to propose a methodological approach to increase the clearance rate of cold cases in The Netherlands and to contribute to the development of intelligence-driven criminal investigations in general police practice and within cold case investigations in particular.

This proposal is based on practical investigative experience and academic knowledge.

Reconstructing scenarios helps convert cold case information into intelligence, which is beneficial to law enforcement agencies in terms of time, resources and prioritising cold cases. Intelligence contributes to the formulation of more effective queries and to a more efficient adaptation of new and existing investigation methods, leading to a higher cold case clearance rate. Moreover, scenario reconstruction creates a link between intelligence and investigation, i.e. between science and practice, which adds to the further development of intelligence-driven investigations.

When carrying out scenario reconstructions, practical implications are expected, as intelligence products are currently not or barely used in practice and science is not yet embedded in the investigational practice.

To move from scenario reconstruction to intelligence-driven criminal investigation, the gap between science and the investigational practice needs to be bridged by persons familiar with both. This study hopes to provide the necessary and relevant impetus to this dialogue.

This chapter explains how economic analysis can contribute to the delineation of the lone wolf’s opportunities and choices in a manner that allows operationally relevant advice to be contributed to the investigative process.

Using a risk-reward analytical framework we examine the lone wolf’s attack method opportunities and choices and identify those attack methods that would be chosen by lone wolves with different levels of risk aversion. We also use prospect theory as an alternative methodology for the determination of the lone wolf’s preference orderings over the available attack methods in a context where he references his actions against those of a predecessor whom he wishes to emulate.

We find that lone wolf terrorists with different levels of risk aversion can be expected to choose different attack methods or combinations of attack methods. More risk averse lone wolf terrorists will choose attack methods such as assassination. Less risk averse lone wolf terrorists will choose attack methods such as bombing, hostage-taking and unconventional attacks. Also, we find that lone wolf terrorists who reference their actions against ‘predecessor’ lone wolf terrorists will choose differently from among the available attack methods depending on which predecessor lone wolf is being referenced.

The analysis provides two different perspectives on terrorist choice but by no means exhausts the analytical alternatives. The analysis focuses on the fatalities and injuries inflicted whereas other perspectives might include different ‘payoffs’ series, including news or media coverage.

The chapter contributes an analysis of the order in which lone wolf terrorists with particular characteristics will choose from a set of available attack methods. During the course of our discussion we point out the consistency between the ‘rise’ of the lone wolf terrorist and the diseconomies to scale that are evident within the terrorism context. This presents the opportunity for new debates.

Traditional crime linkage studies on serial sexual assaults have relied predominantly on a binary crime linkage approach that has yielded successful results in terms of linkage accuracy. Such an approach is a coarse reflection of reality by focussing mainly on the outcome of an offence, neglecting the forceful differences due to the intricate offender-victim interaction. Only few researchers have examined sexual assaults through the lens of a sequence analysis framework. This paper aims to present the first empirical test of offence sequence-based crime linkage, moving beyond exploratory analyses.

Offence accounts from 90 serial sexual assault and rape victims from the UK were analysed and sequentially coded. Sequence analysis allowed to compare all offences combinations regarding their underlying sequence of events. The resulting comparison was transformed and plotted in two-dimensional space by multidimensional scaling analysis for a visual inspection of linkage potential. The transformed proximities of all offences were used as predictors in a receiver operating characteristic analysis to actually test their discriminatory accuracy for crime linkage purpose.

Sequence analysis shows significant discriminatory accuracy for crime linkage purpose. However, the method does perform less well than previous binary crime linkage studies.

Several limitations due to the nature of the data will be discussed.

The practical limitations are as follows: the study is a potential practical value for crime analysts; it is a complimentary methodology for statistical crime linkage packages; it requires automated coding to be useful; and it is very dependent on crime recoding standards.

The exploratory part of this study has been published in a book chapter in 2015. However, to the best of the authors’ knowledge, the succinct test of crime linkage accuracy is the first of its kind.

Currently, no research is available for behavioural investigative advisors’ to provide justifications to infer from the crime scene that an offender is a UK or non-UK national. The paper aims to discuss these issues.

Data were obtained from National Crime Agency and consisted of 651 stranger rapes, 434 UK nationals and 217 non-UK nationals. All cases were coded for 70 offence behaviour variables. χ² analyses were conducted to identify significant associations between offence behaviours and offender nationality. Significant associations were then entered into a logistic regression analysis to assess their combined predictive ability of offender nationality.

Analyses revealed 11 offence behaviours with significant associations to offender nationality: confidence, darkness, offender kisses victim, victim performs sex acts, requests sex acts, apologises, destroys forensics, block entry/exit, weapon – firearm, vaginal penetration – hands/fist/digital, and violence: minimal. From this, seven variables held predictive ability within the logistic regression, with five predicting the non-UK grouping and two the UK grouping.

Future research should test the distinctions between UK and non-UK national stranger rapists and explore the impact of length of residency.

Results indicated that on the whole UK and non-UK stranger rapists display similar behaviours, but there were some distinct behaviours within stranger rape crime scenes, particularly the use of firearms. The ability to use crime scene behaviours to narrow suspect pools by criminal conviction is only useful when police have access to full criminal histories. Unfortunately, the ability to access and search non-UK databases is not always possible. Therefore, this study may be the first step for BIAs to utilise in identifying the likely offender nationality, before using further models that narrow down to criminal history.

This is the first study to examine whether it is possible to differentiate stranger rapists nationality using their offence behaviours.

The purpose of this study was to contribute to the evidence base by analysing the characteristics and motives of homicides involving acts of dismemberment.

The current study explored offence, victim and offender characteristics and the motives for 71 homicides involving dismemberment using open source data. All cases included in this study were investigated in the UK between 1970 and 2016. A non-metric multi-dimensional scaling procedure smallest space analysis (SSA) was used to explore the characteristics and motives derived from a content analysis of homicide data sourced online.

A distinction between expressive and instrumental characteristics was observable with three thematic regions identified: instrumental – defensive, instrumental – predatory and expressive – affective. Support was found for previously identified motives for criminal dismemberment, with defensive being the most common motive identified in 63% (N = 45) of the cases.

The implications of the findings are discussed with suggestions made for future research. The findings have practical implications for assisting law enforcement and forensic and clinical practitioners in further understanding offenders who engage in homicidal dismemberment. This includes aiding homicide investigations, in terms of supporting investigators to draw upon offence, victim and offender characteristics and motives for homicides involving acts of dismemberment. Differentiation between cases of dismemberment and understanding of motives also has practical implications for the development of interventions and treatment pathways for homicide offenders who dismember victims.

Although offender profiling has been cited as an effective tool to interview suspects, empirical profiling methods have completely excluded interviewing suggestions when testing the validity of this technique. The purpose of this paper is to explore the utility of empirically derived profiles of offender- and victim-related sexual assault case characteristics (n=624) in the preparation of the interrogation strategies in sexual assault investigations.

Latent class analysis was used to extract profiles of offender- and victim-related sexual assault case characteristics in a sample of 624 incarcerated sex offenders. Moreover, relationships between offender and victim profiles were conducted using χ² analyses.

Findings show that specific offender-victim profiles are related to greater likelihood of confession during the interrogation. Possible interrogation strategies for each profile are suggested and implications for the practice of interviewing suspects are discussed.

The study is the first to examine both victim and offender profiles in order to assess the significant victim-offender profile combinations and their associated probabilities of resulting in confession.