Forensic science is the application of many other sciences including physics, chemistry, biology, computer science, and engineering to matters of law and order. Forensics science is used by investigators to help understand what happened a crime scene. Every single part of the crime scene is analyzed to find the smallest bits of evidence. Forensic science can help investigators to understand how blood spatter patterns occur, find out who was at the crime scene, when the crime occurred, and who committed the crime. Forensic science is a very important part of the justice system, because it provides scientific facts based on hard evidence. In a typical crime scene investigation, material evidence will be gathered by the investigators. Then the forensic scientists will analyze this evidence to provide a scientific based evidence to be presented in court. Each type of material evidence must be collected in a different fashion to ensure that the evidence remains as intact and un-contaminated as possible. for example: Blood that is in liquid pools should be collected on gauze pads or sterile cotton and allowed to air dry. Then it should be refrigerated. At he standard crime scene, photographs will be taken of everything before collection. Larger pieces of evidence will be removed first, such as a computer, or clothing. The ground should be vacuumed any find trace evidence. There are a number different classification for evidence in forensic science. Circumstantial evidence is