Assessment of Utilisation of Conventional Physical Method to Develop Time Dependent Latent Finger Prints on Non-porous Surfaces: A Cross-sectional Study

A fingerprint is an impression or residue left on any material or surface by the friction ridged skin of the fingers. Fingerprints remain unchanged throughout the lifetime of a person, which serves as a unique characteristic for each individual. The uniqueness of fingerprints lies in their ridge patterns, which are formed during foetal development. There are three types of fingerprints that can be found at the crime scene: patent, latent and plastic fingerprints. Latent fingerprint deposited on different surfaces can be developed with different developmental techniques. Latent fingerprints deposited on non-porous surfaces are developed using a physical method by using various dusting powders such as green fluorescent, pink fluorescent, black powder, aluminium flake, etc. Due to the degradation of fingerprint residue, the development of aged latent fingerprints with a suitable technique for each type of surface might be challenging for a Forensic Scientist. The present study aims to identify the dusting powder that can best develop a time-dependent, clear, and visible latent fingerprint on a non-porous surface. Fingerprints were obtained on glass, wood, and plastic; fluorescent, white, and black powders were used to develop them over a period of 60 days, once every two days. It was found that fluorescent powder was the most effective for developing the fingerprints with very good visibility (Score 5) on glass and wood substrate, while on plastic, the white powder was effective with very good visibility (Score 5). Thus, this study can help in deciding the method to be used in such a situation without causing further delay and loss of vital evidence.