Forensic science is any kind of science used in the legal or justice system to support and uphold the law. When a crime has been committed and evidence is collected at the scene, scientists analyze it, arrive at scientific results and give expert court testimony about their findings. Forensic science concentrates on facts that prove something did or did not happen in a criminal or civil case.
The use of scientific principles to prove guilt or innocence in criminal matters dates back at least to 700 A.D., when the Chinese discovered that every human fingerprint is unique and used this fact to resolve disputes. In the 1800s, scientists developed chemical tests for the presence of blood and began comparing bullets ejected from different firearms. In 1905, President Theodore Roosevelt established the Federal Bureau of Investigation for the analysis of criminal cases. In 1985, Sir Alec Jeffreys of England developed a process for profiling the genetic material, or DNA, of any human being. Today, scientific analysis is central to determining a suspect’s guilt in almost any criminal case.
The American Academy of Forensic Sciences lists 10 categories of forensic science, including biology (life science), psychiatry and behavior science, toxicology (the study of poisonous substances) and anthropology (the study of human remains). However, almost any scientific discipline can be used to analyze evidence in a criminal matter. Insect scientists (entomologists), for example, may study fly larvae (maggots) on a murder victim to help investigators determine time of death. Plant scientists (botanists) analyze plant matter collected at crime scenes and on victims or suspects. Computer science is another discipline increasingly called on to retrieve and analyze digital evidence in criminal cases.
Regardless of their scientific specialty, all forensic scientists have the same goal: examining evidence from a crime scene using strictly scientific knowledge and principles in order to find facts about a criminal case. Because the outcomes are objective facts, forensic science can be useful both to the prosecution and the defense. Any discipline of forensic science can prove whether and how suspects and victims are linked to each other or to the crime scene itself.
Forensic science has become one of the most important parts of any criminal case. Experts who study evidence collected at a crime scene and who explain their scientific findings to a jury make it possible for juries, in turn, to make good decisions about guilt or innocence. Courtroom verdicts are based not on circumstantial evidence or eyewitness accounts but on solid, scientific fact. The more advanced different fields of science become, the more important forensic science will be in court cases and in the role of the justice system to convict the guilty and acquit the innocent.
Forensic scientists must concern themselves with science itself, not the crime. To be useful in a court of law, their testimony must be objective, reliable and based only on scientific fact. If the facts show that no clear conclusion can be drawn, they must state this as their finding. Forensic scientists are not on the side of the law. They are on the side of scientific truth and fact and must stand behind whatever outcome their findings show.