Blood stains are marks left by blood that has come into contact with a surface. They can vary in color from bright red to dark brown, depending on factors like the age of the stain and the amount of oxygen present. Blood stains are often analyzed in forensic science to help solve crimes, as they can provide important information about the events that occurred. The study of blood stains involves understanding patterns and characteristics, such as spatter, drip, and pooling. Forensic experts use these patterns to determine the position of a victim or suspect during a violent incident. This analysis can be crucial in criminal investigations and legal proceedings.