A National Examination of the Spatial Extent and Similarity of Offenders’ Activity Spaces Using Police Data

• Main Authors: Sophie Curtis-Ham, Wim Bernasco, Oleg N. Medvedev, Devon L. L. Polaschek
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: ISPRS International Journal of Geo-Information
• Subjects: homology assumption; geographic offender profiling; offender activity space; police data; routine activity nodes
• Online Access: https://www.mdpi.com/2220-9964/10/2/47

It is well established that offenders’ routine activity locations (nodes) shape their crime locations, but research examining the geography of offenders’ routine activity spaces has to date largely been limited to a few core nodes such as homes and prior offense locations, and to small study areas. This paper explores the utility of police data to provide novel insights into the spatial extent of, and overlap between, individual offenders’ activity spaces. It includes a wider set of activity nodes (including relatives’ homes, schools, and non-crime incidents) and broadens the geographical scale to a national level, by comparison to previous studies. Using a police dataset including n=60,229 burglary, robbery, and extra-familial sex offenders in New Zealand, a wide range of activity nodes were present for most burglary and robbery offenders, but fewer for sex offenders, reflecting sparser histories of police contact. In a novel test of the criminal profiling assumptions of homology and differentiation in a spatial context, we find that those who offend in nearby locations tend to share more activity space than those who offend further apart. However, in finding many offenders’ activity spaces span wide geographic distances, we highlight challenges for crime location choice research and geographic profiling practice.