A laser-based spectroscopy system that combines a distance/proximity standoff sensor, a high-repetition rate laser spectroscopy system, and software with a decision-making algorithm embedded in a processing unit which in combination performs selective firing of the laser when the target object is within an interrogation zone. In a related embodiment, the system provides selective sorting of spectroscopic signals based on information from the standoff signal and from information contained in the spectral signals themselves. The laser emission can be actively controlled while keeping the laser firing, thereby preserving the thermal stability and hence the power of the laser; and the standoff sensor information and the spectral information can be combined to determine the proper relative weighting or importance of each piece of spectral information.