Optical alignment for piston driven chest compression devices optimizes the application of chest compressions to a fixed location on a subject's chest and provides information regarding the depth and frequency of chest compressions. The targeting system records and may display some telemetry corresponding to any movement or “walking” away from the selected compression site as well as the depth and frequency of compressions. The targeting system is interconnected to the compression device controller and the targeting system provides warnings to operators if the compression components contact the subject outside a preset warning limit away from the selected compression site. The targeting system may also halt the compression device if the site of contact between the compression components and the subject is located outside a preset absolute limit.