Crime laboratories (Forensic Science)
Forensic scientists, also known as criminalists, apply scientific methods to the analysis, identification, and interpretation of evidence gathered at crime scenes. They conduct much of their work at crime laboratories, facilities that are specially equipped with the technological and other tools they need to carry out the careful examination of evidence.
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Sherlock Holmes and Early Crime Laboratories (Forensic Science)
A direct connection can be drawn between the detective novels of Sir Arthur Conan Doyle and the establishment of the first crime laboratory. Renowned for the creation of the fictional detective Sherlock Holmes, Doyle was well trained in science. He was a practicing physician with a strongly held conviction that scientific method can be applied logically and effectively to solving crimes. In 1887, Doyle introduced the world to Sherlock Holmes and his sidekick, Dr. Watson. He continued to write about them for the next thirty-five years.
Among Doyle’s most ardent fans was Edmond Locard, a Frenchman who devoured the Sherlock Holmes stories. Convinced of the efficacy of applying scientific method to solving crimes, Locard established the world’s first forensic crime laboratory, the Institute of criminalistics for the Rhone Prefecture of the University of Lyon in France. This early laboratory occupied modest quarters in the Lyon courthouse. Locard, whose laboratory equipment consisted of a microscope and a spectroscope, gained credibility by using scientific means to solve a puzzle surrounding the counterfeiting of coins in the Lyon area. Obtaining some clothes belonging to a suspect, he extracted from them samples of dirt in which he found traces of metal that matched the metal in the counterfeit coins. This discovery caused the suspect to confess and gave people confidence in Locard’s...
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Discovering and Preserving Evidence (Forensic Science)
One of the most important elements in gathering evidence from the scene of a crime or accident is the preservation of that evidence so that it is not contaminated following its discovery. For each piece of evidence, a record (referred to as the chain of custody) is kept of every single person who deals with the evidence from the time it is discovered to the day the evidence is used in court or in some other official venue.
Evidence must be gathered by people trained in forensic science techniques. Before evidence samples are collected for transportation to a crime laboratory, investigators examine the evidence as they find it at the crime or accident scene, which the police preserve as nearly as they can, making it inaccessible to unauthorized or untrained people. In the early stages of an investigation, the scene is photographed from a variety of angles and careful measurements are taken; a forensic artist also sketches the scene.
Among the kinds of evidence that criminalists gather are fingerprints. Surfaces that may hold prints are carefully dusted with a powder that creates strong contrasts in the ridges and valleys of such prints. Fingerprints that are uncovered in this way are first photographed and then are lifted from the surface with a sterile adhesive tape and transferred to a fingerprint card. Visible prints, such as those found on surfaces in blood or grease, are photographed and...
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Laboratory Equipment and Techniques (Forensic Science)
Crime laboratories are equipped with a variety of specialized microscopes that are used to examine closely the materials found at crime scenes. Stereoscopic binocular microscopes are essential for the examination of trace elements detected at the scenes of crimes and are also used to examine and classify handwriting and text created by typewriters and computer printers.
Polarizing microscopes enable forensic scientists to examine and identify minerals, narcotics, and other elements by enlarging their crystal forms. Essential to those engaged in ballistic examinations, comparison microscopes enable forensic scientists to compare the markings on shells and casings found at crime scenes with other samples, possibly linking them to particular weapons.
Using spectrophotometry, investigators can uncover light and heat rays that the human eye cannot see. The spectrophotometer shows the patterns of such rays, and by examining these patterns criminalists can detect alterations on documents, such as erasures, that may indicate fraud or forgery. The gas chromatograph, a sophisticated instrument that identifies the constituent components of substances and measures each component, is used to identify many different unknown substances. It is also the instrument that forensic scientists employ to determine the blood alcohol levels of persons suspected of driving under the influence.
The analysis of DNA...
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Training of Crime Lab Personnel (Forensic Science)
Nearly all law-enforcement officers receive some training in identifying and handling the evidence with which they come into contact at crime scenes. Because of the growing level of sophistication of the work done in crime laboratories, many colleges and universities in the United States have established special programs designed to train forensic scientists.
Generally, one requirement for employment in a crime laboratory in the United States is an undergraduate degree in chemistry or in some aspect of criminology. The undergraduate preparation of forensic scientists usually includes extensive course work in a variety of chemistry subdisciplines as well as courses in anatomy, physics, biology, geology, and psychology.
Some major American universities offer training in forensic science that leads to a master of science degree; some offer doctorates in criminalistics or forensic science. Many institutions of higher learning provide short training courses in forensic science for law-enforcement personnel and for practicing attorneys; these are helpful for persons within the criminal justice system who lack the typical undergraduate background in forensics or who seek to update their training.
Most forensic scientists in the United States work for local, state, or federal public agencies, although some are private consultants for businesses, industry groups, or other private organizations. The...
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Further Reading (Forensic Science)
Baden, Michael, and Marion Roach. Dead Reckoning: The New Science of Catching Killers. New York: Simon & Schuster, 2001. Provides detailed information on how law-enforcement agencies track down criminals through the use of modern forensic techniques. Shows how Sherlock Holmes stories led to the founding of the first crime laboratory in 1910.
Bass, Bill, and Jon Jefferson. Death’s Acre: Inside the Legendary Forensic Lab The Body Farm Where the Dead Do Tell Tales. New York: G. P. Putnam’s Sons, 2003. Presents a fascinating account of the University of Tennessee’s Body Farm, the facility that Bass established to study the process of decomposition of the human body.
Bell, Suzanne. Encyclopedia of Forensic Science. New York: Facts On File, 2004. Provides a brief and incisive account of the development of crime laboratories in France, the United States, and other countries.
Campbell, Andrea. Forensic Science: Evidence, Clues, and Investigation. Philadelphia: Chelsea House, 2000. Overview of the forensic sciences intended for young adult readers includes information about the genesis and importance of crime laboratories.
Conklin, Barbara Gardner, Robert Gardner, and Dennis Shortelle. Encyclopedia of Forensic Science: A Compendium of Detective Fact and Fiction. Westport, Conn.: Oryx Press, 2002. Includes an overall account of crime laboratories and also deals...
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