Fingerprints are considered as one of the most imperative piece of physical evidence for unraveling majority of civil and criminal cases, as fingerprint individuality is highly admissible in the court of law. The most common type of fingerprint found at crime scene is Latent Fingerprint which is left unobserved by the perpetrator. The adoption of method for developing latent fingerprints solely depends on the type of surface, efficiency and simplicity. Latent Fingerprints can be discovered by various methods. Earlier, powder dusting methods including black powder (Haque et al. 1989), fluorescent powders (Kerr et al. 2013), and other synthetic food and festive colors (gulal) (Kumari et al. 2011), ninhydrin dipping (Crown 1969), iodine fuming (Jasuja et al. 2012) and silver nitrate (Dalrymple et al. 1977) were most commonly employed for the development of such prints. These techniques exhibited quite effective results for many surfaces but to increase their efficiency and to simultaneously diminution the price, some advances were needed. Traditional used powders, bears noxious constituents and pose potential health risks. The most common method implied to disentangle the secrets of latent prints is “Powder Dusting Method”. The mechanism of how the fingerprint powder works is explained as: Firstly, the affected area is located then the fingerprint powder is sprinkled over the affected area. The powder adheres to the oils and other constituents of the sweat left in a fingerprint and the print is deciphered. But sometimes only partial or incomplete prints are deciphered. And also sometimes the powders do not give contrast which makes it difficult for the examiner to study and compare the developed prints. To overcome this disadvantage, in this study attempts have been done to develop latent fingerprints using powders which are non-toxic and easily available. The powders used in this study are household products which have so many medicinal uses also.
Turmeric
It is a mixture of phenolic compounds which is called as curcumin and also a volatile oil which contains zingiberene and turmerone (Pandey BP 2003); other monoterpenes and cineole; starch; protein; and high amounts of vitamin A. Gall bladder showed stimulating effects on action of these essential oils. More bile is produced by stimulation through these oils which also help in regulating viscosity in the liver (Figs. 1 and 2).
Cumin powder (cumin)
The presence of a volatile oil in cumin powder (Fig. 3): cumin aldehyde results in strong aromatic smell. Cumin fruits are warm and have bitter taste due to cumin aldehyde which exists in the cumin fruits in the proportion (2.5–4) %. The method of separation of fruit used is distillation with water. Pale yellow colour is characteristic and composed of a mixture of cymene or cymol and cyminol or cuminic aldehyde (Fig. 4). The above mentioned are its chief constituent. Aldehydes that are present in the oil are responsible for the characteristic odor of cumin.
Garam masala
The ingredients differ by region and also according to each individual preferences. In powdered form Garam masala basically consists of CUMIN, CORIANDER, BLACK PEPPER, CARDAMOM, and CINNAMON. In this research work, MDH Garam masala (Fig. 5) has been used for development of latent fingerprints.
Limestone
Calcium carbonate is the basic contituent of Limestone (Fig. 6). Limestone is composed of nearly 50% of carbonate minerals, generally consisting the mineral dolomite (calcium-magnesium carbonate, CaMg [CO3]2) or calcite (pure CaCO3) or even both.
Gram flour
The chemical formula of Gram flour or wheat flour is (C6H10O5)n. It is composed of starches in its polymer form. Starch is a carbohydrate which can be further categorized as an amylase also. The bran and the germ are included in wheat kernel from which the Whole-wheat flour is derived. Color of the wheat flour is brown, and has a nutty flavor. In cooking, whole-wheat flour is used to produce a denser result. Which is result of its thickening abilities.
Coriander powder
Coriander leaves gives aroma which is also the result of presence of aldehyde compounds. The largest proportion of these are those aldehydes which have 6–10 carbon atoms. Particularly decyl (10) and nonyl (9) aldehyde. Other major constituents of the leaves are 2-decenoic acid and decanoid acid and tetradecanoid acid. The chemical composition of coriander is slightly different from its main constituent that is Linalool (Fig. 7).