Blood Stain Patterns
A clear understanding of the scientific principles involved with blood must be emphasized. Depending on the injury, when the blood leaves the body it conforms to the general laws of physics. The analyst must be careful when analyzing the blood shedding events like this will enable them to understand clearly blood flow. The physical properties of blood when in fluid form, have several properties that resemble water characteristics. Both blood and water are affected by physical forces. The internal friction that is present in most fluids is referred to as viscosity. As fluids flow past each other, the layers that are present among them are responsible for the generation of these frictional forces. Also, both cohesion and surface tension forces cause blood drops to maintain their spherical shape once they drop from their point of origin. Cohesion force attracts molecules together while surface tension refers to a force created by the molecules of a fluid when they attain the lowest most stable energy configuration value possible. This value is attained by minimizing the areas that can lead to exposure of the fluid.Impact Spatter usually results from a forceful impact between an object and wet blood. This impact causes the blood to disintegrate into smaller droplets. When the impact is greater, the droplets produced will be much smaller (James, Kish, Sutton 2005). This is due to a drop in the density of blood that decreases as the movement of the blood drops become further from the blood source. A critical analysis of impact splatter enhances the conclusions on the location of the individual.