Question

1. What conclusions can you draw about the effect of height on the appearance of a 2. What conclusions can you draw about the effect of the surface texture of a 3. Hypothesize how different fabric substrates such as cotton, silk, and knitted wool, blood spatter pattern? substrate on the appearance of a blood spatter pattern? may affect the appearance of a blood spatter pattern. Be specific about the characteristics that would have an affect.

Answer 1

Ans. 1. The shape and size of the blood spatter entails the force with which the blood was propelled. The larger spattering indicates an adjacent area of the effect or event that has occurred. Height is an important parameter to delineate the height from which the action took place, which will help us in identifying the origin of the blood spatter, using the angle of impact. Moreover, the height will ascertain the shape of the blood spatter i.e., the greater the height from the origin of blood, larger will be the impact. The angle of impact can be determined by measuring the width of spatter to length. The higher the height the higher will be the radius if the spattered blood forms a circular shape. With the increase in height, the density of the color will decrease.

Ans. 2. The surface texture of the affected substrate determines the fate of a blood spatter. If the surface is flat or smooth, then an elongated shape is formed with the tail directed towards the direction of the propagation. The spatter will be with smooth edges. On the contrary, when the texture is rough, non porous, the stain will be more or less circular in shape and with rough edges. The first contact pattern of the stain will be taken by the blood in case of its transition. In case of folded surface, it will exhibit butterfly shaped forms. Horizontal surfaces exhibit increase in volume of blood over a vertical surface, and vertical surface will exhibit downward flow pattern.

Ans. 3. Fabrics tend to absorb the blood and take the stain immediately with their respective patterns. These have been described below:

• In any clothing or fabric if that was placed on a hard surface, the material exhibits conspicuous and distinctive patterns whereas in a soft surface the fabric absorbs most of the blood.
• Pure cotton materials exhibit majorly, an irregular shaped stains whereas some stains are oval or rectangular, or diamond and various other shapes. On the other hand linen mixed cotton shows a higher amount of irregularity in shape of about 77 %.
• An interesting characteristic is exhibited by vinyl - it does not let blood soak too deep and are flaky.
• In nylon materials there is about 70 % of irregular shape with distinct pooling and lesser wicking. There is usually increase in stain size with increase in height with lesser overlapping of the stains.
• Mixed polyester clothing often gives an upward directed stain. Polyester does not exhibit a varied shape irregularities, the shapes are mostly irregular and ranges between round to rectangular.
• Silk material exhibits extensive pooling and satellite spatter.
• In the terry clothes the stain sizes decreased with height as they passed through the pores.
• In woolen clothes, the stain takes the convex shape, which upon drying forms a dense stain. Stains with the most minute diameter is exhibited in this type of fabric. There is a higher overlapping of stains.