Forensic evidence is evidence obtained by scientific methods such as ballistics, blood test, and DNA test and used in court. Forensic evidence often helps to establish the guilt or innocence of possible suspects. Analysis of forensic evidence is used in the investigation and prosecution of civil as well as criminal proceedings. Forensic evidence can be used to link crimes that are thought to be related to one another. For example, DNA evidence can link one offender to several different crimes or crime scenes. This linking of crimes helps the police authorities to narrow the range of possible suspects and to establish patterns of for crimes to identify and prosecute suspects.