Techniques/Chemicals Used to Develop Fingerprints

With any surface, the first technique to use for finding fingerprints is optical techniques. Optical techniques are when different types of lighting, such as ultraviolet light, is used to expose otherwise invisible prints. On a porous surface, you have to find out whether or not the surface where the print was left was wet. If it was, more than likely the latent fingerprints will not turn up. On dry porous surfaces, DFO, ninhydrin, and metal salt treatment are different technique options. On nonabsorbent surfaces, after finding the fingerprint, put powder (white for dark surfaces, black for light colored/glass surfaces) over the print, then dust the extra powder away to make-out the print.