Sequential angulation, spatial dispersion and consistency of distance attack patterns from home in serial murder, rape and burglary

Abstract

Three related measures of spatial movement (sequential angulation, spatial dispersion and consistency of distance in attack target) were compared across three serial offence types: serial homicide (n=35), serial rape (n=41) and serial burglary (n=30). In each case, each offender had committed at least five offences. “Spatial dispersion”, defined as the extent to which an offender distributes his offences across either a focused or relatively more evenly distributed area, revealed that burglary was less evenly distributed (i.e. more focused) than rape and murder. “Sequential angulation”, defined as the degree of rotational movement around the home of the offender from one offence to the next, revealed that serial murderers have higher angulation scores than do rapists who, in turn, have higher angulation scores than burglars. Lastly, a comparison of the offender's consistency in the relative distance travelled from home to each attack site (“consistency of distance in attack target”) was relatively similar across the three groups. This was despite the comparison of different serial offence types from disparate geographical areas. The supposition that differences in dispersion and sequential angulation scores across crime types are related to the perceived risk of the crime has been confirmed. The specificity and the mobility of the targets are also discussed.

Keywords:

• Geographical profiling
• offender consistency
• serial offenders
• sequential angulation
• spatial dispersion
• attack patterns

Notes

1 Obtained from Dr Christoper Missen, formerly of the Centre for Investigative Psychology, Liverpool. Dr Missen has posthumously left the data with Professor David Canter, Head of the Centre.