Interpretation of bloodstain patterns on fabrics

This study investigates factors causing distortions in bloodstain patterns on various types of fabric that may be present at crime scenes or worn by individuals involved. The aim was to provide a foundation for interpreting bloodstain evidence through visual comparisons. An experimental design was applied across seven fabric types and one control surface (A4 paper) using a four-stage process to simulate bloodstain formation. Blood droplets were applied to each surface, and the resulting stains were examined both macroscopically and microscopically in terms of their size, shape, and pattern characteristics. The study demonstrated that identical physical impacts produce different stain appearances depending on surface texture and absorbency. These differences can significantly affect the accuracy of reconstructing impact angles or source positions, especially when distortions such as irregular edges or satellite stains are present. Furthermore, the research highlighted specific visual cues that distinguish between spatter, transfer (wiping, smearing), and passive drip patterns, even when they appear similar. A key finding is that experimental bloodstains used for comparative purposes should be produced on the same fabric type to ensure valid interpretation. The study concludes that accurate analysis requires comprehensive consideration of factors, such as fabric material, texture, moisture content, blood properties, and environmental conditions.