A plane problem for optimization of stationary sensors placement in a threat environment to counteract an evading object is considered. For this purpose, an auxiliary task of constructing locally optimal paths of the evading object for a given configuration of sensors is solved. Integral risk functional is minimized for the evading object. The minimum of this functional is required to be maximized in the task of sensors placement. The paper describes the methods of solving both problems and the results of numerical modeling for the case of 2 sensors: examples of local optimal path maps, and the best found configurations of sensors placement.