What type of person may have committed this crime? This is one of the fundamental questions in the area of profiling. Criminal profiling, is based on the idea that behaviour reflects personality, which means that by examining crime scene behaviour investigators will be able to determine the type of person that is responsible for the crime (Douglas, Ressler, Burgess, & Hartman, 1986). There are a number of aspects of their sexual crimes that have non-sexual but still distinctly criminal components, such as the wearing of a mask to hide the offender's identity, or the carrying of a weapon to the crime scene. It is hypothesised that offenders who commit many of these actions are likely to have extensive history of non-sexual crimes. (Canter, 1990). There are seven variables that can be interpreted as reflecting criminality: