|MadSci Network: Chemistry|
Dear Tasha, Good question, and scientists have asked the same question, and several set out to find the answer. Scientists knew for some time that a fingerprint left at a scene, called a latent print, consisted of the residue left behind when someone touched something. This residue consists mostly of water, about 99%! The rest of the material consists of fats, oils, salts, and in some cases, DNA. Over the years, police officers and scientists have noticed that the latents left behind by young children disappear faster than those of adults, and scientists have speculated that children's latents may have more volatile components which evaporate faster. I have listed the following articles that you can get from a library which should help answer your question as to the specific chemical nature of latent prints. I hope this helps. Dale L. Laux Forensic Scientist S. K. Bramble, "Separation of latent fingermark residue by thin-layer chromatography," J. Forensic Sci. 40, 969 (1995). M. V. Buchanan, K. Asano, A. Bohanon," Chemical characterization of fingerprints from adults and children," in Forensic Evidence Analysis and Crime Scene Investigation, J. Hicks, P. R. De Forest, V. M. Baylor, eds., Proc. SPIE 2941, 89 (1997). R. A. H. van Oorschot, M. K. Jones, "DNA fingerprints from fingerprints," Nature 387, 767 (1997). G. M. Mong, C. E. Petersen, T. R. W. Clauss, "Advanced fingerprint analysis project fingerprint constituents," Pacific Northwest National Laboratory, Richland, WA 99352, report PNNL-13019, Sept. 1999. "Vanished Into Thin Air: The Search for Children's Fingerprints", Anal. Chem., July 1, 1995, pp. 435A-438A.
Try the links in the MadSci Library for more information on Chemistry.