A Novel Approach to Latent Fingerprint Development Using Onion <i>(Allium cepa)</i> Powder

Introduction: 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. Methods: 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 ec-crine fingerprint is deposited on a non-porous surface. The surfaces used in the study in-cluded 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: Results indicated that onion powder effectively developed latent fingerprints on both types of surfaces, highlighting its potential as an alternative to traditional fingerprint powders. Conclusion: This innovative method not only broadens the scope of fingerprint development techniques but also presents a cost-effective and readily available option for forensic appli-cations. The findings underscore the versatility and efficacy of onion powder in forensic fin-gerprint analysis, offering a promising avenue for future research and practical implementa-tion.