Question

what would be the best method to develop a fingerprint on: skin
ninhydrin
superglue (cyanoacrylate)
iodine

Explanation:

Ninhydrin reacts with amino - acids in fingerprints but is more suitable for porous surfaces. Superglue (cyanoacrylate) fumes can be used to develop fingerprints on non - porous surfaces like skin. Iodine is also used for fingerprint development on some materials but superglue fuming is a common method for skin due to its ability to adhere to the residue left by fingerprints on skin's surface.

Answer:

superglue (cyanoacrylate)