Current Forensic Science - Current Issue

In forensic chemistry, the examination of evidence collected from explosion sites continues to be a significant field of research, driven by the growing need for enhanced homeland security in response to terrorist and warfare risks. A terrorist arranges a detonation cord to place a charge on an improvised explosive device. In India, detonating cords are widely utilized in mining. Pentaerythritol tetra nitrate (PETN) is the most exploitable high explosive used as an explosive core within the plastic covering of detonating cord. There has been significant attention given to the detection of PETN as an explosive because of concerns related to military and public safety.

The rapid detection of PETN has become increasingly important in real crime samples because of its low vapor pressure and thermal liability. The main objective of the present study was to rapidly identifying PETN in crime samples (intact and defused detonating cord) of forensic laboratories using chromatography and spectroscopy methods.

Spot tests, thin layer chromatography (TLC) and Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy (ATR-FTIR) spectroscopy methods were used to indentify PETN in intact and disposed form of detonating cord.

PETN was been preliminary detected in spot tests and TLC. As ATR-FTIR do not use high temperature or thermal desorption, it was used in present study for confirmation of PETN in seized real crime samples of detonating cord in intact and disposed form.

The integration of multiple techniques enhances detection reliability in forensic chemistry. ATR-FTIR spectroscopy proved to be an important technique without the use of other chemical/other instrumental analysis and easily classify among different samples received for the forensic opinion.

Naturally occurring substances, including quercetin and sulphur compounds, which are recognised for their antioxidant and adhesive characteristics, are found in onion powder, which is made from dried onions. These characteristics make onion powder a suitable choice for the formation of latent fingerprints. Our research investigates a novel approach using onion (Allium cepa) powder as a fingerprint-developing agent for both sebaceous and eccrine fingerprints on a variety of porous and non-porous surfaces.

The methodology for sebaceous fingerprints involves ensuring the hands of the donor are clean and free of any extraneous substances before depositing the fingerprint on a selected surface, followed by the application of onion powder with an Ostrich hair brush. For eccrine fingerprints, the hands of the donor undergo a thorough cleansing with soap, water, and acetone, followed by a 45-minute period of wearing unpowdered latex gloves to enhance the presence of eccrine secretions. After glove removal and gentle finger massaging, the eccrine fingerprint is deposited on a non-porous surface. The surfaces used in the study included non-porous materials like iron, glass, steel, aluminium foil, and ceramic tile, as well as porous materials like black paper, leather, rubber, plastic, and cardboard. Hygiene was maintained using ethanol, soap, cotton, and gloves throughout the procedure.

Results indicated that onion powder effectively developed latent fingerprints on both types of surfaces, highlighting its potential as an alternative to traditional fingerprint powders.

This innovative method not only broadens the scope of fingerprint development techniques but also presents a cost-effective and readily available option for forensic applications. The findings underscore the versatility and efficacy of onion powder in forensic fingerprint analysis, offering a promising avenue for future research and practical implementation.