Offenders who target children are a negative phenomenon in our society. These offenders are often seen as the worst of the worst of criminals and are therefore a priority for investigators trying to solve these crimes as fast as possible. The purpose of this thesis is to see if there are common denominators among these offenders in their modus operandi (MO) and their spatial patterns. If similar patterns emerge amongst these offenders, that would be of investigative importance for those who work with crimes against children. In Study I, a group of child molesters and their MO were studied in order to see how they found their victims and where they committed their crimes. The results were consistent with previous studies on child molesters in that they all committed their crimes at home or close to their homes. In Study II, a geographical profiling tool was tested in order to see if such a program could be used to find an offender who made obscene phone calls (OPC) to children. The results showed that the geographical software based on spatial behaviour, was able to narrow down the search area in which the offender actually lived when he committed his crimes. In Study III, the focus was on the potential witnesses/victims and how much a child could remember correctly of a staged event simulating a potential child molester looking for new victims. The results showed that the children’s event memory were comparable with an adult control group. The combined results could be summarized as follows: offenders who target children usually commit their crimes at home or close to home (or base), they tend to lure children to go with them by using bribes or the recruitment of former victims. Girls seem to be the preferred sex over boys. Children could be used as accurate witnesses in these types of crimes.

Two experiments examined the realism in the confidence of 8-9-year-olds, 12-13-year-olds and adults in their free recall and answers to focused questions after viewing a short video clip. A different video clip was shown in each experiment and the focused questions differed in difficulty. In both experiments the youngest age group, in contrast to the two other age groups, showed no overconfidence in their confidence judgements for the free recall. The free recall results also showed that the youngest group had lower completeness but similar correctness as the adults. There was a tendency, over both experiments, for the participants to show poorer realism for the focused questions than for the free recall, especially when questions with content already mentioned in the free recall were excluded from the analyses of the focused questions in Experiment 1. The study shows the importance of question format when evaluating the credibility of the confidence shown by 8-9-year-old children in their own testimony.

Studies on geographical profiling have typically focused on crimes with physical crime sites. This study focused on crimes with no physical crimes sites (i.e. no physical contact occurred between the victim and the offender). A single offender made obscene phone calls to 86 children during the years 1999-2000 in the south of Sweden. The locations in which obscene phone calls were received were analysed in a geographical profiling system (Dragnet) to see whether it could provide a map that showed the most likely area the offender would reside in. The purpose of this study was to explore whether geographical software such as Dragnet can be used by investigators of crimes with no physical crime locations. The result showed that the offender in this case had his home close to the region assigned the highest probability of containing home or base, which indicates that Dragnet can provide maps that can narrow down the search areas for the police in cases without physical crime locations.