• A criminal investigation is an applied science that involves the study of facts, used to identify, locate and prove the guilt of an accused. A complete criminal investigation can include searching the immediate area of a crime for evidence, interviewing persons that live and work in the area of the crime scene, persons¬†that are known to loiter in the area. Collection and preservation of evidence such as blood samples, cement, grass, and soil and documentation of evidence using video and photography are quite helpful. ¬†