A method and system for detection and identification of concealed materials, is provided, wherein a dark image and two or more NIR sample images are taken at two or more key wavelengths or bands of wavelengths corresponding to peaks and/or valleys in the NIR spectra of known materials, and differential wavelength imaging processes are used to produce a differential wavelength image based on therein. The differential wavelength image is then analyzed/processed so as to detect any materials concealed on the target of interest, such as a human or piece of baggage, by calculation of pixel intensity values in the image and identification of distinctive pixel values. Then, via various methods, the distinctive pixel values of the detected materials are compared to a data set of known wavelengths related to known materials, such as explosives and other contraband. Correspondence thereof results in an accurate identification of the concealed material(s).