Physical Characteristics of Spatter Stains on Textiles: Influence of Impact Surface Texture, Blood Drop Volume and Blood Drop Velocity

Statement of the Problem: Bloodstains commonly occur at violent scenes and may provide useful information about how the stains were created. This information can be useful to corroborate or refute witness statements. However, when bloodstains occur on textiles, the interaction between blood and the textile structure can greatly alter the stain pattern, thus rendering the analysis of the stain difficult, impossible or even invalid. This proposal attempts to define key characteristics that are useful for forensics analysis by (1) fully characterizing target textile substrates, (2) projecting individual, well-characterized blood drops (volume, velocity) onto the textile at (3) well defined impact angles and (4) orientations to the textile texture. The resulting stains will be analyzed for drop breakup on impact with the textile, penetration into the textile, and wicking within the textile to determine characteristics which distinguish these stains from others, such as transfer and expirated. This project contains a research and/or development component, as defined in applicable law, and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14). CA/NCF