  This paper presents an algorithm to deploy a team of {\it free} guards
equipped with omni-directional cameras for tracking a bounded speed intruder
inside a simply-connected polygonal environment. The proposed algorithm
partitions the environment into smaller polygons, and assigns a guard to each
partition so that the intruder is visible to at least one guard at all times.
Based on the concept of {\it dynamic zones} introduced in this paper, we
propose event-triggered strategies for the guards to track the intruder. We
show that the number of guards deployed by the algorithm for tracking is
strictly less than $\lfloor {\frac{n}{3}} \rfloor$ which is sufficient and
sometimes necessary for coverage. We derive an upper bound on the speed of the
mobile guard required for successful tracking which depends on the intruder's
speed, the road map of the mobile guards, and geometry of the environment.
Finally, we extend the aforementioned analysis to orthogonal polygons, and show
that the upper bound on the number of guards deployed for tracking is strictly
less than $\lfloor {\frac{n}{4}} \rfloor$ which is sufficient and sometimes
necessary for the coverage problem.
