The application of scientific knowledge and methodology to legal problems and criminal investigations. Sometimes called simply forensics, forensic science encompasses many different fields of science, including anthropology, biology, chemistry, engineering, genetics, medicine, pathology, phonetics, psychiatry, and toxicology. The related term criminalistics refers more specifically to the scientific collection and analysis of physical evidence in criminal cases. This includes the analysis of many kinds of materials, including blood, fibers, bullets, and fingerprints. Many law enforcement agencies operate crime labs that perform scientific studies of evidence. The largest of these labs is run by the Federal Bureau of Investigation. High-impact journals are those considered to be highly influential in their respective fields. The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind.