Abstract
The interpretation of bloodstains on textiles can be complicated by post-depositional changes during decomposition. In enclosed environments, volatile organic compound (VOC) condensation and insect activity can alter or obscure bloodstains. This study examined bloodstain alteration and insect artefact formation on cotton and polyester fabrics exposed in sealed, perforated, and intact containers housing stabbed, fabric-wrapped piglets. Swatches bearing porcine blood were affixed to container walls and recovered over 131 days, alongside field and laboratory controls. Concealed swatches exhibited discolouration from VOC condensation, diluted blood appearance, and insect artefacts, while field swatches showed fading and minimal insect contamination. Insect eggs, regurgitate, faeces, and puparia were frequently observed on container swatches and wrappings, particularly under humid conditions. The results demonstrate that concealment, insect access, and fabric type affect bloodstain visibility and insect artefact formation. Differentiating these effects is essential for accurate bloodstain pattern analysis in cases involving concealed decomposed remains.