Fig. 4.

Crime hotspot suppression. Suppression results for the PDE system with parameters chosen to generate supercritical or subcritical crime hotspots (see SI Methods). (A) Suppression of supercritical crime hotspots. Shown is the configuration of supercritical hotspots at timestep t = 100, just prior to the introduction of crime suppression. Crime suppression is then introduced over the area of each visible hotspot, leading to the eradication of the original hotspots but corresponding increases in risk in neighboring regions, seen at t = 120. The transient structure at t = 120 resembles a hot ring solution surrounding the location of the original central hotspot. By the time of the next suppression at t = 200, a new steady state featuring hotspots in positions adjacent to the original ones has been achieved. (B) Suppression of subcritical crime hotspots. Shown is a central subcritical hotspot at t = 100, just prior to the introduction of crime suppression. Crime suppression is then introduced over the area of the hotspot, leading to the eradication of the hotspot by t = 120. No transient structures appear in this case. Eventually suppression is lifted at t = 200 and the system quickly adopts the homogenous steady state. Colors scale as explained in Fig. 2.