Système d'information géographique
Hotspots are the foundation of crime concentrations because it is from the hotspot's earlier theories and studies that the analysis of crime concentration was derived. Hotspots can be expressed in the form of dots, lines or polygons and even shades of color as in the case of kernel density which estimates the likelihood of a crime event occurring within a given region; this is done through "crime mapping" which refers to the allocation of individual or multiple crime incidents on a map by utilizing a computer software package such as ArcMap 10.1, a Geographic information system. The different forms of hotspots and consequently crime concentrations are studied and explained by various theories and measured by several spatial and temporal analysis techniques. These techniques generally rely on statistical algorithms for the creation of surface maps. One of predominant theories that explains crime congregations is Crime opportunity theory. It explains that "rather than concentrations of offenders or the absence of social controls, opportunity theories suggest that analysts should look for concentrations of crime targets". Repeat victimization%20theory Victimisation victimization theory examines why some areas or targets are repeatedly victimized. Broken windows theory also explains that an area that becomes abandoned or if the guardians and managers cease to be in control of an establishment, then other guardians and managers become less motivated to enforce social controls, consequently allowing criminal activity to increase. Lastly, one of the most influential crime concentration theories is the Crime Place Theory because it focuses on criminal events on specific locations rather than a large view at the high crime density area.