CRIMINOLOGICAL RESEARCH REPORT

Transcription

1 CRIMINOLOGICAL RESEARCH REPORT With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

2 Research Report Criminology 1 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

3 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs 2

4 Foreword... 5 B-CCENTRE Project objectives for the Criminological research track... 6 How to achieve both objectives?... 6 Executive Summary Studies Studies Conclusion Partners Applicant Organisation/Coordinator Manager Ann Mennens Researchers Prof. Dr. Stefan Bogaerts Marjolein Brusselaers Karel Demeyer Jenny Houtepen Marjolein Missler Janneke Schilder Jelle Sijtsema Publications - Abstracts Circumventing internet parental control and online pretending in primary school children: Family related differences and predictors The Effectiveness of an Intervention to promote Awareness and Reduce Online Risk Behaviour of Belgian Primary School Children The influence of parental supervision on online risk behaviour among young children: a gender perspective Privacy, Risk, Information protection and Social Network Site-Using Behaviour in a Sample of Flemish University Students From child pornography offending to child sexual abuse: A review of child pornography offender characteristics and risks for cross-over Being sexually attracted to minors: Sexual development, coping, and risk factors for offending in self-identified pedophiles Helping the police investigation: police investigation applied to sex offenders by using network sampling Full Text Articles Circumventing internet parental control and online pretending in primary school children: Family related differences and predictors The Effectiveness of an Intervention to promote Awareness and Reduce Online Risk Behaviour of Belgian Primary School Children With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

5 The influence of parental supervision on online risk behaviour among young children: a gender perspective Privacy, Risk, Information protection and Social Network Site-Using Behaviour in a Sample of Flemish University Students From child pornography offending to child sexual abuse: A review of child pornography offender characteristics and risks for cross-over Being sexually attracted to minors: Sexual development, coping, and risk factors for offending in self-identified pedophiles Training Tool for Police and Aid Workers Risks and Vulnerabilities in offences with Pedophilia and Child Pornography With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

6 Foreword The Belgian Cybercrime Centre of Excellence for Training, Research and Education is Belgium s central coordination, collaboration and knowledge sharing platform in the fight against cybercrime. B-CCENTRE coordinates research teams at various universities which collaborate across disciplines on specific cybercrime, cybersecurity and cyberforensics related topics in both fundamental and applied research activities. Together with experts from public sector and industry partners, the academic B-CCENTRE partners design and teach basic and advanced trainings on specific cybercrime topics and develop and implement awareness raising initiatives in Belgium. B-CCENTRE does not only focus its efforts on a national level, but engages in the fight against cybercrime beyond the Belgian borders through numerous contacts with similar centres abroad. B-CCENTRE is the Belgian node in the European network of Cybercrime Centres of Excellence and collaborates with the main European and international organisations dealing with cybercrime. It is sponsored by the Prevention of and Fight against Crime Programme of the European Union, under contract HOME/2010/ISEC/AG/INT-011, and co-funded by the academic partners, under the coordination of the KU Leuven. The B-CCENTRE started its activities in spring 2011 and has since launched and supported numerous activities to enhance knowledge and sharing of information and expertise related to cybercrime, digital forensics, cybersecurity, online behaviour and risks, privacy, data protection and other related topics in Belgium and beyond. This book provides an overview of the results of the criminological research performed in the frame of the EU sponsored B-CCENTRE project, 18 April November There is a similar publication on the results of the legal and of the technical research performed. These three publications are complementary to the B-CCENTRE report of activities. For further reading we refer to the B-CCENTRE publications section under the research tab on our website, where you can find the links to the articles published in the frame of the B-CCENTRE project. On the site you can also find information about B-CCENTRE partners and activities as well as an overview of relevant actors, education programmes and awareness raising activities in Belgium and other interesting leads. We wish you an interesting read and welcome your feedback on the work done. Ann MENNENS Manager B-CCENTRE KU Leuven iminds ICRI/CIR Sint-Michielsstraat 6, box 3443, BE-3000 Leuven ann.mennens@b-ccentre.be Disclaimer: All publications listed represent the opinion of their author(s) and do not represent the official position of the B-CCENTRE, nor of the European Commission on the topics discussed 5 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

7 B-CCENTRE Project objectives for the Criminological research track In the B-CCENTRE Project, Work package 4 (CR1 and CR2) deals with the criminological aspects of cybercrime. The studies made in this package had two objectives from criminological and forensicpsychological perspective: The first objective was to conduct fundamental and applied scientific research on cybercrime and child pornography (CR1); The second objective was to develop educational material, tools and best practices, and transferring this knowledge and application to relevant field organisations, such as forensic psychiatric clinics (policlinic and clinic) and the police (CR2). To achieve both objectives, collaboration was established between the University of Leuven; Leuvens Institute of Criminology - LinC (Belgium), and Tilburg University, Department of Developmental Psychology, research line Forensic Psychology (the Netherlands). Both universities cooperate with the police (police Rotterdam and Tilburg), justice (public prosecutor Rotterdam, Tilburg), and a self-help group for child sex offenders who didn t come into contact with the police, the justice system, and forensic psychiatric treatment centres. Further, cooperation was also organised with two forensic psychiatric centres (FPC) and with one policlinic forensic centre and daycare centre (FPC Gent and FPC de Kijvelanden, DOK) in Belgium and in the Netherlands. How to achieve both objectives? Study of online behaviour of primary school children (9-11) In preparation to reach both research objectives, a very large (n = 1437 children), and explorative, quasiexperimental and prospective research was performed in in primary schools to examine online behaviour of Flemish children between 9 and 11 years old. This research resulted in several studies. We opted to examine online behaviour of primary school children for several reasons; first, very young children are already (extremely) active on the internet; second, very young children are often seen as forgotten online victims notwithstanding they are likely to become victimized on the internet by peers or adults. In our study, we saw that about 10% of the children reported to have met in real life an unknown adult they had met on the internet, what can be seen as problematic, despite the fact that the data were obtained through self-report and children sometimes fantasize and exaggerate. Third, we talk constantly about online risk behaviour while we have little understanding of online baseline behaviour, especially of young children. We developed a questionnaire for primary school children to study normal and abnormal online behaviour. The questionnaire consists of about thirty questions concerning, e.g., age, grade, country of birth of mother and father, brothers and sisters, the use of internet, the use of a computer, tablet, Smartphone, whether they had online contact with family, friends or strangers, peers or adults; whether they ever met online strangers in real life; why they use the internet: for school, games, others; whether they were ever bullied on the internet or they had ever bullied someone else. 6 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

8 We constructed an intervention and examined, prospectively whether awareness of dangers on the internet increased and resulted in online behavioural changes (less risky behaviour). Why this study? Insight in cybercrime can only make sense if there is insight in basic behaviours on the internet (to start with young children as an important target group). A major problem is that parents, school, police and government often speak of risky online behaviour while very little is known about baseline online behaviour (of youngsters). Therefore, research on online baseline behaviour is necessary what can lead to school interventions and interventions of parents what is, however, not the primary objective of this research. This preliminary research resulted in three studies (see further in this report). Study of digital protection behaviour of young adults In addition, among a group of young adults (n = 488), all students at the Catholic University of Leuven (Computer Science, Law and Criminology), we examined how these young adults behave with online protection rules and securing their computer. Further we examined whether following (or not) protection guidelines and the way they secure their computers is related to personality traits. This resulted in one study that is reflected in this report. Study on predators of child pornography and offline sex offenders Subsequently, we conducted two important studies on predators of child pornography and offline sex offenders. A first study was a systematic review on offenders of child pornography. The main reason to perform this systematic review was, firstly the fact that child pornography offenders can be seen as a very heterogeneous group. Secondly, mental health practitioners must make a distinction between paedophiles and child molesters, and child molesters and rapists (minor and adult victims), because this distinction is very important for therapists (diagnosis, treatment indication and treatment tools), and it gives the police information about the chance of (sexual) recidivism. For the benefit of forensic treatment on the one hand, and police enforcement on the other hand, it was important to give clarity in this heterogeneous group for individual risk assessment, treatment planning and detection. A second, empirical study was conducted among a very exceptional group, namely 15 self-identified paedophiles that were recruited through a Belgian and Dutch self-help group. Through this study, we provided more insight into risk and protective factors of child sexual offending in paedophiles, and the development of paedophilic feelings in general by studying self-identified paedophiles outside clinical and forensic settings. This specific group of self-identified paedophiles can also be seen as a hidden population that is hardly known by mental health institutions and the police. Both studies are described in this report. With this study, we make the move to the last study that has this hidden population as target. Study on hidden population of sex offenders Hidden population of sex offenders is rather a large group; research shows that the chance of being caught as an (online) sex offender is rather low. This has to do with difficulties in detecting and arresting (online) sex offenders on the one hand. On the other hand the unwillingness and impossibility of victims to report to the police is relatively high (often because they are forced by the perpetrator not to report), and offers the police weak indicators to detect the suspect. This detection problem was the immediate reason to conduct the last study in which we introduced a social network tool for the police that can be very helpful in tracking down (online) sex offenders. The same tool can also be used by mental health practitioners to get more insights in 7 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

9 protective and risky network configuration of sex offenders and child pornography downloaders after discharge from prison or mental health institution. The results of this study can be found in this report. The results of these studies have led to a number of different products that can be classified into supportive tools and professional group-specific tools. 8 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

10 Supportive tools (1) Circumventing internet parental control and online pretending in primary school children: Family related differences and predictors (M.B.J. Brusselaers, S. Bogaerts, & K. Demeyer); (2) The Effectiveness of an Intervention to promote Awareness and Reduce Online Risk Behaviour of Belgian Primary School Children (J.D. Schilder, M.B.J. Brusselaers, & S. Bogaerts); (3) The influence of parental supervision on online risk behaviour among young children: a gender perspective (M.A. Missler & S. Bogaerts); (4) Privacy, Risk, Information protection and Social Network Site-Using Behaviour in a Sample of Flemish University Students (Z. Horváth, S. Bogaerts, & Karel Demeijer). Notwithstanding the importance of these studies, we see them rather as supportive; not just for parents and teachers, but also for police, public prosecution and mental health care. In the many conversations we had with these actors, it came forward that they mostly have to deal with problematic cases of victims and offenders, and that very little information is available about risky behaviour of children on social media and how an intervention can lead to behavioural change. Their interest in the behaviour of young children on the internet can be described as follow: "Children have no idea of dangers on the internet but behave in social media as if they are adults. These children can become the victims and perpetrators of tomorrow. Raising awareness at a very young age and see if an intervention actually helps is essential". Five products were developed specifically for the police and justice (detection, arrest and prosecution) and/or for forensic mental health. Professional group-specific tools (5) From child pornography offending to child sexual abuse: A review of child pornography offender characteristics and risks for cross-over (J.A.B.M. Houtepen, J.J. Sijtsema, & S. Bogaerts); (6) Being sexually attracted to minors: Sexual development, coping, and risk factors for offending in selfidentified pedophiles (J.A.B.M. Houtepen, J.J. Sijtsema, & S. Bogaerts); (7) PowerPoint presentations in Dutch, English and French that have been presented in Leuven and Rotterdam to a large group of mental health professionals, teachers and law enforcement (J.A.B.M. Houtepen, J.J. Sijtsema, & S. Bogaerts); (8) Helping the police investigation: police investigation applied to sex offenders by using network sampling (M. Spreen, S. Bogaerts, & M.A. Misller). (9) Instructions, guidelines and a step-by-step example of how to use UCINET to develop a network configuration to support police investigation and risk management of sex offenders and possessors of child pornography. These tools were presented in FPC Kijvelanden, DOK (the Netherlands) and recently in FPC Ghent (Belgium). Forensic Network Analysis is currently used in both Dutch organisations in the framework of risk management of (online) sex offenders. This tool shall also be used in spring of 2015 in the FPC Ghent. Forensic Network Analysis, more specific B-graph network sampling was presented to 4 detectives who were involved in the detection of (online) sex offenders and will hopefully be implemented in the near future by the Belgian and Dutch police. 9 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

11 Executive Summary Studies 1-4 Notwithstanding internet and social media tools offer many advantages for children and adults, there is always the risk to get hurt. Children are especially vulnerable for this, but so are adults. The internet and social media are very easily accessible and at first glance very innocent and easy in use. In other words, children and adults who have little understanding of risks or who are prone to be manipulated can very quickly become deceived on the internet without being aware of deceptions. Parents and teachers can explain children what the dangers of the internet are but very often, they not always have enough knowledge and technical skills about internet applications and risk, or have insufficient possibilities to observe the online behaviour of the children. The internet is everywhere, on computers, tablet, smartphone and is constantly within reach. Despite parental supervision, filter software and usage restrictions, some children try to avoid these support frameworks by circumventing parental control and by online pretending. We know very little of the prevalence and possible predictors of circumventing parental control and online pretending in youngsters, and whether this behaviour is different for boys and girls, differs between ages, family structure and the country of birth of the parent(s). A representative sample of 1437 Flemish primary school children was set up in cooperation with more than 45 primary schools in the Flemish part of Belgium. All children were 8-12 years old and followed the second (third year) or third grade (fifth year) of primary school. All children were written and orally questioned in class about their basic internet behaviour (f.e., number of hours on the internet per day and in the weekend, types of social media they were on, with whom they had contact on the internet, parental control and supervision, bullying behaviour on the internet, victim of bullying and knowledge of the parents of the internet). The survey took place in the schools and was coordinated by one or two researchers who were always in class. The questions were read by the researchers, and children could ask for information when something was unclear. We saw that circumvention of parental control and online pretending was reported by more than 50% of all children. We found that birth country of both parents resulted in significant differences in circumventing parental control on the one hand, and online pretending on the other hand. Parental control was lower for children with a parent born in Belgium compared to children with a non-eu originated parent, at least according to the reporting of the children. We found that the level of online pretending was significantly higher for male 5 th graders and for children from a non-traditional family. Secondly, just because children use the internet long before their first years of primary school and the importance to study online risky behaviour at early age, it seems to be important to understand parental attitudes and the role of parents as they, especially in primary school children, have very important influence on children especially between the ages of 8-12 years. At that age parents are more important than when children go to secondary school and the influence of peers and friends becomes more and more prominent. Therefore, we studied the influence of parental mediation, namely parental supervision on online risk behaviour among the whole sample of 1,437 children in both 3rd and 5th grade of primary school and investigated whether gender differences occur. We found very interesting gender differences and gender patterns. For girls, it was found that online risk behaviour was negatively associated with parental supervision and school grade. That means that for girls, online risky behaviour decreases when parental supervision increases, which was not found in boys. For boys, non-traditional family structures and children from the 5 th grade were significant predictors of online risk behaviour. Children from single-parent families and composite families, and older children (5 th grade), exhibited more online risky behaviour than children from more 10 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

12 traditional families and children of the 3 th grade. We also found that an active and communicative approach by parents was more effective in lowering online risk behaviour among girls than a passive and non-communicative approach. After four months, a second measurement was performed in approximately 20 schools (less than half of the original schools). The smaller sample for the second study was drawn from the complete sample of more than 1,400 children. Before conducting the second measurement, children were classified by the researchers into a high-risk and low-risk online group based on 12 indications of online risky behaviour. Both groups, together, counted over 800 children. After that, both groups were randomised classified into an intervention group and a control group; half of the children of the high-risk group received the intervention or control condition. The same happened in the low-risk group. The intervention group received information about danger behaviours on the internet. This information was given by the researchers by showing the children a PowerPoint presentation that took about 10 minutes. Each sheet was explained by the researcher without being suggestive. In contrast, the control group received neutral information about the internet, such as games on the internet, etc. and no information was given about online risks. The purpose of the intervention was to examine the awareness-effect and behavioural-effect after the intervention or control condition and to examine differences between the intervention and control group. The second measurement took place immediately after both conditions and was instructed and coordinated by one of the researchers in class. After about four months, all 800 children who were involved in the intervention/control conditions were questioned again (third measurement), to examine whether awareness/behaviour about online risks continued or not. The general hypothesis was that awareness of online risks would increase in the intervention group compared to the control group in both the high and lowrisk group. It was further assumed that between the intervention and the third measurement (four months following the intervention), a decrease of awareness was found and online risk behaviour would rise again. This increase would be especially observed in the high-risk group. We found that children in the intervention group compared to children in the control group were much more likely to be aware of online risks and although diminishing, online risk awareness was still noticeable four months after the intervention and remained higher in the intervention group than in the control group. This pattern was found, especially in the high-risk group, but also, to a lesser extent in the low-risk group. This finding was in line with the general hypothesis. However, against our expectations and in opposite with the hypothesis, the intervention did not seem to diminish the amount of online risk behaviour. Four months after the intervention, we found that children in the intervention group were even more likely to report online risk behaviour. This means that the intervention had an impact on the awareness of dangers on the internet, but no transition happens from awareness to behavioural changes. A gender difference was observed: girls were more likely to be aware of the online risks directly after the intervention than boys were. Girls and children in 3 th grade were less likely to behave in a risky manner when online. We also concentrated on online behaviour of young adults and more particularly of university students from computer science, law and criminology. For this study, an online survey was conducted among almost 500 students. We examined potential influential factors related to the degree to which students are concerned about online privacy, online risk and the way they are (or not) engaged in information protecting behaviour. We examined a series of predictors such as, unpleasant experiences on social network sites, experiences of privacy invasions, type of education (computer science, law and criminology), gender, age, and the personality trait extraversion. We assumed that age, gender, type of education, unpleasant experiences, extraversion, and privacy invasion significantly contributed to privacy concerns. More particularly, age, gender, type of education, unpleasant experiences, extraversion, and privacy invasion were expected to significantly contribute to risk concerns and to information protection. We found that students who scored 11 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

13 higher on extraversion, showed a larger online social network size than students who scored lower on extraversion. Results show that extraverted students had a larger online social network size, the majority of the participants had a Facebook profile, were most active on Facebook, used social network sites more than twice per day, were between 1 and 5 hours a week occupied with checking their profiles, had their total number of friends between 201 and 300, and updated their profile more than twice a week. Most of the participants had read the privacy policy but not carefully. Our results also showed that education type and privacy invasion were significant predictors of privacy concerns, with privacy invasion having the largest contribution. Students who studied computer science took more precautions on the internet than students who studied law. Criminology students scored the worst on security concerns. Studies 5-9 Following studies focussed on (online) child molesters, paedophiles and rapists to gather information and tools for mental health professionals, police and public prosecutor. As already mentioned in the objectives, our first goal was to understand typologies of deviant sexual behaviour and to gain more insight into online predators, paedophiles, child molesters, rapists and generalists. The latest group is e.g., online predators that also show cross-over sexual behaviour what means that they both commit crimes online and off-line. As it is known from numerous studies, child molesters commit very often sexual and non-sexual crimes, and both children and adults can be victimised. Otherwise, paedophiles can be characterised more as specialists, often limited to sex crimes and seeking for a relationship with children. They don t use violence and force very often. In our first study, we conducted a systematic review to give more insight in the heterogeneity of (online) child sex offenders in order to provide tools for individual risk assessment, treatment planning, police detection and information about recidivism rates. Based on reviewing offender characteristics, including demographics, socio-affective difficulties, cognitive distortions and psychosexual issues, we found that, despite individual differences, many child pornography offenders suffer from psychological difficulties in multiple areas of psychological, social and professional functioning. We found that risk factors of especially online offenders can be seen along the lines of two continua: the first continuum is characterised as features related to criminal behaviour; in the second continuum, the presence of sexual deviance/fantasy and cognitive distortions is apparent. Both continua gave insight into pathways and psychological differences between offender types, but also allow practitioners and police officers to detect variation in the severity of psychological difficulties within offender types, and therefore may enhance individual risk assessment, interviewing strategies and treatment. Further, information of the background of sex offenders also gives us more information in the severity of a crime and victim injuries. In this study, we also discussed cross-over behaviour, factors related to engagement with the internet, the offline environment and the combination of both online and offline sexual deviant behaviour. This information is important for mental health services and the police. A systematic review is very interesting to bring together a lot of research to distillate sexual deviant patterns (criminal and antisocial pathway and a more sexual deviance pathway), as we did above. However, a large group of sex offenders (online and offline) is missing in current research; most studies on (online) sex offenders took place in prisons and forensic mental health institutions. Most studies are carried out on well known and identified sex offenders. However, this group of known sex offenders is a selective group of sex offenders who have been arrested and forced to mandatory treatment. Only a very small group of (online) sex offenders asked voluntarily for mental health. 12 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

14 The group that is hidden from the police and mental health services is called the 'hidden population or the dark number group. These sex offenders barely have come in contact with the police and with mental health. It is, of course, the question what characteristics are typical in this group of unidentified sex offenders and whether this group differs from the detected group sex offenders. A study of this unidentified group is difficult because these individuals are difficult to trace but a study on unidentified sex offenders cannot be missing in this study. As explained earlier, we found a method to interview 15 self-identified sex offenders what offers a great contribution to both mental health and the police. By interviewing those 15 self-identified sex offenders, we provided more insight in risk- and protective factors for child sexual offending in paedophiles, and the development of paedophilic feelings in general. We studied self-identified paedophiles outside clinical and forensic settings. An important question is how they survive and what kind of skills they have to (self)-regulate their sexual and emotional feelings toward children. Two studies were conducted. In the first study, 15 paedophiles were interviewed about sexual development, coping, and ways to relief sexual arousal. Most paedophiles mentioned that they often became aware of their sexual attraction to children in early puberty, and that their sexual preference continued into adulthood. Many of them struggled with those paedophilic feelings and experienced psychological problems such as anxiety and feelings of depression. Many of them were less or more engaged in child sexual offending in puberty when they were still discovering their sexual feelings and sexual identity. Therefore, early recognition of risk factors and early start of interventions seem vital in preventing (online) sex offenses. What we found is that there is an urgent need for sufficient help to support paedophiles in their acceptance of paedophilic feelings, and in finding non-harmful ways to relief their sexual arousal without making victims. In our second study, we compared those 15 self-identified paedophiles to a control group of 62 adult males on risk factors for offending. We found that paedophiles were more likely to have a history of abuse in childhood and experienced more negative life events before the age of 16 years compared to the control group. These findings were in line with previous research in the last three decades. Numerous studies are published about victimisation and witnessing domestic violence, psychological, physical and sexual abuse in the family of origin. Compared with normal controls, sex offenders recalled, regardless of the type of sex offender, significantly more frequently victimisation of neglect and abuse in childhood and youth. Sex offenders reported significantly more insecure attachment styles with parents and caregivers in childhood and intimacy problems with romantic partners in adulthood. Assuming an intergenerational approach, it can be stated that there has been a reversal: especially boys who were victimised or have witnessed violence in their family in childhood and youth, are more at risk to become an aggressor in adulthood. This is also found in girls but to a much lesser extent. Finally, let s return to the group of 'hidden sex offenders' and the fact that the detection and monitoring of sex offenders is very difficult. The following recent Dutch press release is an example of this (July, 18 th 2014): Arrest of the Utrecht serial rapist: There is a big breakthrough in the case of the Utrecht serial rapist. A suspect is arrested after 20 years. It is a 51-year-old man from the vicinity of Utrecht. The suspect has been convicted of bicycle theft earlier this year. He had to give the police his DNA. It turned out that his DNA-profile matched with the DNA from three cases, two from 1995 and one from The match was found by the Dutch Forensic Institute on Tuesday 15 th July. The man was arrested and brought before the judge. The suspect is not a stranger to the police. Twice before, 13 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

15 he was named in the research but there was little evidence to see and arrest him as a suspect. In 1995 and 1996, five women were raped in Utrecht and surrounding area. For a few years, it remained silent; until 2001, another rape took place by the same perpetrator. Justice brings the man also in relationship to 12 other attempts to rape. Knowledge about hidden populations is important for forensic and investigative psychology, criminology, police investigation, justice and mental health risk management. Hidden populations are f.e., drug users, illegal immigrants, illegal prostitutes, human traffickers, rapists and (online) child abusers. These groups succeed reasonably easy in hiding from the police because they seldom leave traces on the crime scene and because they are geographically mobile. Geographical distribution also requires cooperation with other regions what is not easy and requires coordination. The example of the serial rapist in Utrecht shows very well that it has lasted 20 years before the suspect could be arrested; in this specific case, thanks to a DNA match that was taken by coincidence after a bicycle theft. In this case, DNA traces were found but in many cases, tracks are destroyed by the offender and very often, victims are unable to observe the perpetrator and to give useful information to the police. Because the police very often has a lack of clear investigative directions, it s the question whether there are methods to detect specific groups of criminals, such as sex offenders. A method that is often applied in criminology is the capture-recapture method. This is an interesting method that is based on the assumption that a hidden population can be estimated by using registered individuals in this hidden population from, e.g., police databases or mental health databases. However, a problem that very often occurs is that the quality of databases is bad to perform capturerecapture method. This is very often the case, or because there are no databases at all. Because capturerecapture often fails, sampling networks can be seen as an interesting method and an alternative to help the police to find hidden targets, f.e., in the detection of unknown sex offenders. On the basis of a hypothetical example, a network sampling method was presented in this report that gives resources to the police to perform their investigation in a better and more structured way. We also included software and learning tools and the illustration of how this method works was explained step by step. Information on the software and learning tool is also in the report. 14 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

16 Conclusion This study can be seen as a multi-method study because we used multiple data sources: a prospective explorative research was conducted among about 1,400 children from primary school. The research design was explorative and prospective (repeated measurements). A second database was obtained through an online survey that consists of nearly 500 university students (computer science, law and criminology); a third database was set up consisting of 15 self-identified sex offenders. We used both quantitative and qualitative research methods (statistical analyses, interviews and systematic review). The delivered products: articles, PowerPoint presentations in different languages and the tool to perform social network analysis to use in police investigation research, can contribute to a better and more efficient detection of sex offenders by the police. We portrayed the first four studies as supportive studies. However, these studies are also vitally important for the police, public prosecution and mental professionals to gain insight into basic behaviours of young children and adults. The reason for that is that children of today very frequently consult social media, unknowingly, can be confronted with online risk behaviour initiated by themselves or by others. Those children can become victims and/or perpetrators of tomorrow. Prevention is better than cure. 15 With the financial support from the Prevention of and Fight against Crime Programme of the European Union European Commission Directorate-General Home Affairs

17 Partners Applicant Organisation/Coordinator KU Leuven KU Leuven is the largest academic institution in Belgium and one of the oldest European universities as it was founded in 1425 ( It is a research-intensive, internationally oriented university that carries out both fundamental and applied research. It is strongly inter- and multidisciplinary in focus and strives for international excellence. To this end, KU Leuven works together actively with its research partners at home and abroad. With a research expenditure of 365 million in 2012, the KU Leuven is a leading research university in Europe. KU Leuven is also a member of the League of European Research Universities (LERU), a group of twenty European research-intensive universities committed to the values of high-quality education in an internationally competitive research environment. More than 200 KU Leuven researchers are permanently working on information and communications technology related issues. They belong to different university departments with a strong tradition in multidisciplinary research on information and communications technology issues. The Interdisciplinary Centre for Law & ICT - ICRI ICRI is co-ordinating the activities of the Belgian Cybercrime Centre of Excellence for Training, Research and Education - B-CCENTRE. The Interdisciplinary Centre for Law & ICT ( is a research centre at the Faculty of Law of KU Leuven dedicated to advance and promote legal knowledge about the information society through research and teaching of the highest quality. ICRI is among the founding members of the LEUVEN Centre on Information and Communication Technology (LICT) and the Flemish ICT Research Institute iminds. Currently, ICRI is part of the iminds Security Department, a de facto one-stop-shop for ICT security research. ICRI is committed to contribute to a better and more efficient regulatory and policy framework for information & communication technologies (ICTs). Its research is focused on the design of innovative legal engineering techniques and is characterised by its intra- and interdisciplinary approach, constantly aspiring cross-fertilisation between legal, technical, economic and socio-cultural perspectives. By conducting ground-breaking legal research in a spirit of academic freedom and freedom of inquiry, ICRI aspires to a place among the centres of excellence in the area of law & ICT in Europe and beyond. LINC Launched in January 2007, the Leuven Institute of Criminology (LINC - is composed of about seventy professors and assistants involved in criminological research and education within the Department of Criminal Law and Criminology of the KU Leuven Faculty of Law. LINC is the most recent institutional incarnation of the criminological tradition in Leuven that started with the establishment of the "School for Criminology" in LINC intends to continue the Leuven tradition of combining solid research with a deep commitment to society. This goal is achieved through fundamental as well as policy-oriented research that is organised around 8 research lines. 16

18 Co-beneficiaries Universiteit van Tilburg (UVT) Department of Developmental Psychology and Forensic Psychology The department of Developmental Psychology at Tilburg University consists of a group of researchers interested in development and individual differences over the life span. With a focus on early infancy on the one hand, and adult developmental processes, on the other hand, the research group pools experts in different stages of development. Using a broad spectrum of research designs and methods, such as shortand long-term longitudinal studies, behavioural genetics, and neurophysiological methods, the research is aimed at describing, explaining, and predicting the development of individual differences. Important outcomes include attachment, social-emotional processes, stress reactivity, personality, and deviant/delinquent behaviour. 17

19 Manager Ann Mennens Ann Mennens is the Manager of the B-CCENTRE Project. She started working in September 2011 at ICRI, KU Leuven to organise the work of the Belgian Cybercrime Centre of Excellence for Training, Research and Education. She coordinates the activities of several academic research groups, public sector bodies and businesses in Belgium dealing with cybercrime. She initiates, supports and manages interdisciplinary research on cybercrime and cyber security, the development and teaching of basic and advanced cybercrime trainings. She is active in setting up and creating awareness raising initiatives related to safe online experiences, both for businesses and organisations, as well as the general public. She is representing the B-CCENTRE in conferences and working groups in Belgium, the EU and worldwide. She is one of the founding members of the Belgian Cyber Security Coalition, a coalition of public authorities, the academic world and the business sector joining forces against cybercrime in Belgium. It brings together more than 50 key players to share knowledge, raise awareness among citizens and businesses and issue recommendations for a more efficient policy. For over 20 years, she has led various projects in the field of Justice and Security, involving governmental and other actors from the EU Member States and beyond. The fight against crime and cooperation between judicial authorities and law enforcement in the EU, have been at the core of the projects under her management. She has a track record of creating networks and systems for cooperation, information exchange and dissemination and of organising training programmes for several target groups, in particular Police and Judiciary. 18

20 Researchers Prof. Dr. Stefan Bogaerts Between 2006 and October 2014, Stefan Bogaerts was one day a week appointed as professor of Criminology at the Research unit of Criminal Law and Criminology at KU Leuven, Belgium. He is one of the principal investigators of The Belgian Cybercrime Centre of Excellence for Training, Research and Education responsible for the criminological and psychological research. Since 2005, he was also part-time full professor of forensic psychology at Tilburg University, Department of Development Psychology, since 2010 responsible for the education in forensic psychology and since 2012 appointed as vice-chair of the Department. In 2014, he made the full switch to Tilburg University. In addition, he works as the head of research and treatment innovation, psychotherapist and supervisor at the Forensic Psychiatric Center Kijvelanden/DOK and FPC Gent, and is doing research on causes and deregulation processes of aggressive behaviour and victimisation. Since 2008, he examines online risk behaviour and vulnerability factors of online aggression and victimisation. Currently, he is involved in several (inter)national research projects on cybercrime and online sexual deviant behaviour, and concentrates on self-regulation and deregulation processes and the development of problematic personality. He wrote about 125 articles, chapters and books in the field of forensic psychology, victimology and criminology. Marjolein Brusselaers Marjolein B. J. Brusselaers works as a junior researcher at the Leuven Institute for Criminology (Catholic University of Leuven). Her research interests include the interconnection between online behaviour of minors, its psychological impact and the educational field. Within the B-CCENTRE project she investigates the link between online risk behaviour in primary school children and child/family characteristics as well as children s coping responses to unpleasant online experiences. Therefore she collaborates closely with Prof. Dr. Stefan Bogaerts, Janneke Schilder, MSc and Marjolein Missler, MSc. She is involved in preparing the material for presenting the B-CCENTRE research results. She holds a Bachelor s degree in Applied School and Pedagogical Psychology and a Master s degree in Clinical Psychology Specific Teacher Training in Human Sciences. Karel Demeyer Karel Demeyer obtained a Master s degree in both Criminological Sciences and Applied Computer Sciences. At ICRI KU Leuven he was part of the team setting up the B-CCENTRE. He worked at the Leuven Institute for Criminology (Catholic University of Leuven) from 2011 until During this period he was together with Professor Bogaerts responsible for the data collection for the B-CCENTRE research study and he was also involved in the data analysis. 19