Final answer:
The two primary categories of bloodstain pattern taxonomy are passive bloodstains, such as drops, flows, and pools, and projected bloodstains, which result from forces like cast-off from weapons or arterial spurting. Tools like a cell counter can aid in systematic blood analysis.
Step-by-step explanation:
The two primary categories of bloodstain pattern taxonomy are passive bloodstains and projected bloodstains. Passive bloodstains are the patterns created from the force of gravity alone. They include drops, flows, and pools, and generally occur when blood drips or flows freely from a source onto a surface. In contrast, projected bloodstains result from an applied force that is stronger than gravity, such as cast-off from a weapon, expiratory blood blown out from the nose or mouth, or arterial spurting from a breached artery.
They tend to show a directionality which can be analyzed to understand the events that caused the bloodshed. Understanding and interpreting these patterns require knowledge of biological fluids and can play a crucial role in forensic analysis. Tools such as a cell counter and methods for systematic scanning, like the evaluation of blood smears mentioned in Figure 5, are essential for accurate analysis of blood samples in the laboratory.