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.