Forensics is defined as the application of science to interpret clues for crime investigation. The earliest forensic scientists were physicians who were called upon to give an opinion as to the cause of death in individuals. Now most of the forensic scientists are investigators that pick up clues at the crime scene. Because criminals often are not the brightest people on the planet they often do not plan out a burglary or theft and carelessly leave behind distinct clues that allow an investigator to track them relatively easily. There are many areas of forensics which include: general crime scene investigation, forensic chemistry, forensic toxicology, forensic pathology, genetic fingerprinting, fingerprinting and chromatography. The purpose of crime scene investigation is to help establish what happened (crime scene reconstruction) and to identify the responsible person. This is done by carefully documenting the conditions at a crime scene and recognizing all relevant physical evidence. The ability to recognize and collect the evidence is important in solving and prosecuting violent cases. In majority of the cases, the law enforcement officer who protects and searches the crime scene plays major part in determining whether the physical evidence will be used in solving or prosecuting the violent crime. Crime scene investigation is not what we think it is, unlike the movies, is actually a difficult and time consuming job. There is no substitute for a careful and thoughtful approach. One should not leap into conclusions as to what happened based on what little information he has with him or her, but generate several theories of the crime, keeping the ones that have not been crossed out by incoming information at the scene. Reasonable inferences about what happened are produced from the scene and appearance and information from witnesses. These theories will help guide the investigator to document specific conditions and recognize valuable evidence.