A porous item is a surface that contains openings that allow for the absorption of liquids to go through the material. One of the typical examples of porous materials is raw wood as it can absorb liquids or fingerprints oils especially if it is not varnished. Chemical development can be done through fingerprint processing of natural wood that is from a physical developer. Fingerprints can be developed through chemical processes of a silver based reagents that prints are produced, and they become gray colored (Trozzi 2001).
In a crime scene, you can get wood outdoors, and this can also be spotted in a construction yard. When the fingerprint is developed raw wood is then photographed and lighting through fluorescents helps illuminate the wood. When the prints have been elaborated from the natural wood, it is then necessary to photograph the item. Through photography preservation of the fingerprint is enabled (Salama 2008).
Ninhydrin is a chemical reagent that is used and sprayed on items that include paper. Paper items form reactions with amino acids in the process of getting fingerprints. The ninhydrin can be utilized together with the solution, and this can be integrated through spraying and dipped and the paper item is allowed to lose the solution and become dry. During the process, the paper is allowed to stay for a matter of days, and the prints appear purple. Dependent on the period one may use a steam iron to increase the reaction times. Preservation has to be done through photography as the prints are susceptible to fading.
References.
Salama, J., Aumeer-Donovan, S., Lennard, C., & Roux, C. (2008). Evaluation of the Fingermark Reagent oil red O as a Possible Replacement for Physical Developer. Journal of Forensic Identification, 58(2), 203.
Trozzi, T. A., Schwartz, R. L., Hollars, M. L., Leighton, L. D., Trozzi, Y. E., & Wade, C. (2001). Processing guides for developing latent prints. Federal Bureau of Investigation.
