1. A sensor system comprising: an illumination subsystem disposed to provide light at a plurality of discrete wavelengths 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 spatially distributed multispectral image from the received light at the plurality of discrete wavelengths; and instructions for comparing the derived multispectral image with a database of multispectral images to identify the individual.