1. A sensor system comprising: an illumination subsystem disposed to provide illumination light to a skin site of an individual; a detection subsystem disposed to receive light scattered from the skin site; and a computational unit interfaced with the detection subsystem and having: instructions for deriving a plurality of spatially distributed multispectral images from the received light, the plurality of spatially distributed multispectral images corresponding to different volumes of illuminated tissue of the individual; and instructions for identifying the individual from the derived plurality of multispectral images.