Detection of Blood Concealed Under Progressive Layers of Different Types of Automotive and Household Paint Using Luminol

Blood is critical evidence in crime scenes, and perpetrators often conceal it using multiple layers of paint. This study aims to detect blood hidden beneath various automotive and household paints available in the Indian market, specifically in Kerala, using Luminol, a reagent known for its chemiluminescent properties. The impact of the number of layers of paint on chemiluminescence and the detection of blood, comparing the effectiveness of automotive and household paints, and examining variations among different paint types within each category were also subjected to study. Two surfaces were used for this study: a brick for household paint and a bumper for automotive paint, with a total of eight different paints (four from each category). Around 5 progressive layers of paint was used to conceal blood. Blood was spattered on the surfaces and was later concealed using progressive layers of paint. it was then detected using Luminol, which was then critically analysed and photographed. Results showed that concealed blood could be effectively detected through all layers of both paint types. Automotive paint provided better concealment than household paint, and variations in chemiluminescence were noted among different paints of the same category. It could be concluded that Luminol is effective in detecting concealed blood, with the type of paint and number of layers influencing detection outcomes.