There are multiple techniques available that can be used to develop latent fingerprints from porous surfaces such as paper. One such technique is referred to as ninhydrin fuming (Eksinitkun et al. 21). Ninhydrin is a chemical that forms a purple compound when it reacts with amino acids. Before soaking into a shell for development, white powder ninhydrin has to be dissolved in acetone. This reaction leads to the development of the prints within a day through the period can be reduced through heating like a household steam iron (Eksinitkun et al. 22) Due to its purple color, the prints formed can be easily photographed.
On the other hand, superglue fuming, also known as cyanoacrylate fuming, utilizes superglue fumes to develop latent fingerprints. These particular prints are those left on surfaces due to sweat and oils emanating from finger pores. The process is done together with water in a developing chamber, and this ensures that the vapors adhere to the given fingerprint, making them visible enough (Thompson). The glue reacts with proteins, amino acids, and fatty acids in the latent fingerprint, which triggers the moisture to produce the seen sticky white material which develops along fingerprint ridges. Eventually, an image of the full latent fingerprint creates, which can be directly photographed or enhanced for a better view. Nonetheless, it is essential to ensure that the glue remains in a gaseous state during this process. In this regard, the technique is straightforward and effective, and it can be done on both old and new fingerprints.
This method was discovered in the late 1970s in Japan by the members of the US Army CID Lab. However, before this, it all started as an accident when a Japanese company was testing ways to package superglue when someone noticed white crystalline fingerprints on the glue’s surface, and this is how the method caught the attention of these scientists who formally introduced it to the scientific world (Thompson). The scientists noted that superglue had reactions with latent fingerprints’ moisture so that the latent print on a non-porous surface was encompassed in a hard coating that captured the latent print’s delicate ridge structure.
This process of superglue fuming requires only two reagents, water, and superglue. The superglue reacts with fatty acids, amino acids, and proteins to enhance the development of latent fingerprints (Thompson). On the other hand, water provides the much-needed vapor for the development of a good print. This moisture is what the superglue reacts with in combination with the other materials. With these two, one can easily obtain desired latent fingerprints.
Nonetheless, in the process of superglue fuming, one of the active ingredients in Drano can be used. Drano is a known drainage cleaner containing sodium hydroxide or sodium hypochlorite and it creates a reaction that decomposes organic matter, leading to blockage. However, in the case of superglue fuming, the active ingredient is sodium hydroxide. This active ingredient is utilized primarily for accelerating the process of the reaction (Thompson). When sodium hydroxide is dissolved in water, it leads to an extremely exothermic reaction that causes the superglue to produce its fumes before the process regains its normalcy. This way, no heating is necessary, and one does not have to wait for 24 hours or more to get the required results. This makes the process one that can be quickly done within the household as the primary materials can be easily accessed or improvised accordingly.
Works Cited
Eksinitkun, G et al. “Simple Improvement in Latent Fingerprint Detection with Ninhydrin/Water Glue on Thermal Paper.” Journal Of Physics: Conference Series, vole 1380, 2019, pp. 21-22. IOP Publishing, Web.
Thompson, Robert. “The Home Scientist 009 – Forensic Fingerprinting III: Superglue.” YouTube, uploaded by TheHomeScientist, Web.