Final answer:
The difference between mid velocity spatter and cast off spatter lies in their size, velocity, and patterns. Mid velocity spatter results from moderate energy impact and has a specific size range, whereas cast off spatter reflects the motion of a bloodied object, creating linear patterns.
Step-by-step explanation:
To tell the difference between mid velocity and cast off spatter in a forensic context, one must examine the characteristics of the bloodstains. Mid velocity spatter is usually associated with blunt force trauma and can produce bloodstains that are 1 to 4 millimeters in diameter. This type of spatter occurs at a velocity of about 5 to 25 feet per second and generally indicates a moderate energy impact to the blood source.
Cast off spatter, on the other hand, is blood that has been flung from a bloody object, such as a weapon in motion. These stains typically create linear patterns of varying sizes, reflecting the arc of the object’s movement. Analyzing these patterns can give investigators insight into the number of blows delivered and the hand used by the assailant.
While the information provided does not directly describe bloodstain patterns, it does explain how momentum and projectile motion can affect the distribution of particles, which is relevant to understanding how blood droplets behave when subjected to force and motion.