Optimal patrol routes: interdicting and pursuing rhino poachers

Abstract

Interdiction patrolling (also known as hot spots policing) is a proactive police operation that depends on good planning. And the pursuit of fleeing suspects is a challenging operation that all police forces engage in on a regular basis. We give software tools that improve the effectiveness of both. We demonstrate the effectiveness of our tools by applying them to the case of rhino poaching in wildlife reserves. An interdiction patrol pre-emptively seeks out poaching parties within a reserve. Upon picking up the trail of a poaching party, a pursuit team needs a pursuit strategy that optimizes their chances of an interception. Our interdiction patrol route tool identifies optimal interdiction patrol routes to walk. This tool is based on a Stackelberg game and represents different types of poachers and their utilities. These utilities are updated (learned) each time new information on poaching party routes is added to the database. Our second tool provides a real-time sequence of team member moves that maximizes the team’s chances of apprehending a pursued party. We show that our tools perform well when applied to simulated and real data.