Blood Evidence
Blood is the best known as significant evidence in modern criminal justice. Blood evidence is important to an investigator because it can link a victim to a suspect (Locards Exchange Principle). Bloodstain patterns can reveal a great deal about the position and movement during the crime. Blood has managed to destroy self-defense arguments from the suspects. The fluid portion of the blood consists of plasma and serum while the non-fluid portion consists of red blood cells. Blood is composed of water, cells, protein, enzymes and other inorganic substances. Blood is thicker (more viscous) than water and flows more slowly than water. When taking the temperature blood will read at 100.4 degrees F and have a pH of 7.4. Blood makes up 8% of total