Bloodstain pattern analysis is a forensic technique used to examine the shapes, sizes, and distribution of bloodstains at a crime scene. By studying these patterns, forensic experts can determine the type of force that caused the bloodshed, the position of the victim and assailant, and the sequence of events during the incident. This analysis relies on the principles of physics and biology to interpret how blood behaves when it is expelled from a source. It can provide crucial evidence in criminal investigations, helping to reconstruct the events leading to a homicide or other violent crime.