a baggage scanning system and method employ combined angular and energy dispersive x - ray scanning to detect the presence of a contraband substance within an interrogation volume of a baggage item . the interrogation volume is illuminated with penetrating , polychromatic x - rays in a primary fan beam from a source such as a tungsten - anode x - ray tube . an energy - dependent absorption correction is determined from measurement of the attenuation of the fan beam at a plurality of different energies . radiation coherently scattered by substances in the interrogation volume is detected by an energy - resolved x - ray detector operated at a plurality of scattering angles to form a plurality of scattering spectra . each scattering spectrum is corrected for energy - dependent absorption and the corrected spectra are combined to produce a scattering pattern . the experimental scattering pattern is compared with reference patterns that uniquely characterize known contraband substances . the system and method can locate and identify a wide variety of contraband substances in an accurate , reliable manner . the system provides for automated screening , with the result that vagaries of human performance are virtually eliminated . false alarms and the need for hand inspection are reduced and detection efficacy is increased .