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Forensic experts apply scientific principles and methods to the analysis, identification, and classification of physical evidence relating to criminal (or suspected criminal) cases.They do much of their work in laboratories, where they subject evidence to tests and then record the results. They may travel to crime scenes to collect evidence and record the physical facts of a site. Forensic experts may also be called upon to testify as expert witnesses and to present scientific findings in court.
In Scotland during the late 1780s, a man was convicted of murder when the soles of his boots matched a plaster cast of footprints taken from the scene of the crime. This is one of the earliest recorded cases of the use of physical evidence to link a suspected criminal with the crime.
In the late 19th century, scientists learned to analyze and classify poisons so their presence could be traced in a body. At about the same time, a controversy arose over the different methods being used to identify individuals positively. Fingerprinting emerged in the early 20th century as the most reliable method of personal identification. With the advent of X-ray technology, experts could rely on dental records to substitute for fingerprint analysis when a corpse was in advanced stages of decomposition and the condition of the skin had deteriorated.
Forensic pathology (medical examination of suspicious or unexplained deaths) also came into prominence at this time, as did ballistics, which is the study of projectiles and how they are shot from firearms.
The study of ballistics was aided by the invention of the comparison microscope, which enabled an investigator to look at bullets side by side and compare their individual markings. Since individual gun barrels “scar” bullets in a unique pattern, similar markings found on different bullets may prove that they were fired from the same weapon.
These investigations by pioneer forensic scientists led the courts and the police to acknowledge the value of scientifically examined physical evidence in establishing guilt or innocence, confirming identity, proving authenticity of documents, and establishing cause of death. As the result of this acceptance by the legal and law enforcement communities, crime laboratories were established. One of the first, largest, and most complete laboratories is that of the Federal Bureau of Investigation (FBI), founded in 1932. Today, the FBI laboratory examines many thousands of pieces of evidence each year, and its employees present their findings in trials all over the United States and around the world. As the forensic sciences proved their worth, crime laboratories were established in larger cities and by state police departments. These laboratories are used in turn by many communities too small to support labs of their own. The scientific analysis of evidence has become an accepted part of police procedure, and new forensic advances, such as DNA testing, are being developed every day.
Forensic experts, also called criminalists, use the instruments of science and engineering to examine physical evidence. They use spectroscopes, microscopes, gas chromatographs, infrared and ultra violet light, microphotography, and other lab measuring and testing equipment to analyze fibers, fabric, dust, soils, paint chips, glass fragments, fire accelerants, paper and ink, and other substances in order to identify their composition and origin. They analyze poisons, drugs, and other substances found in bodies by examining tissue samples, stomach contents, and blood samples. They analyze and classify blood, blood alcohol, semen, hair, fingernails, teeth, human and animal bones and tissue, and other biological specimens. Using samples of the DNA in these materials, they can match a person with a sample of body tissue. They study documents to determine whether they are forged or genuine. They also examine the physical properties of firearms, bullets, and explosives.
At the scene of a crime (whether actual or suspected), forensic experts collect and label evidence. This painstaking task may involve searching for spent bullets or bits of an exploded bomb and other objects scattered by an explosion. They might look for footprints, fingerprints, and tire tracks, which must be recorded or preserved by plaster casting before they are wiped out. Since crime scenes must eventually be cleaned up, forensic experts take notes and photographs to preserve the arrangement of objects, bodies, and debris. They are sometimes called on later to reconstruct the scene of a crime by making a floor plan or map pinpointing the exact location of bodies, weapons, and furniture.
One important discipline within forensic science is identification. Fingerprint classifiers catalog and compare fingerprints of suspected criminals with records to determine if the people who left the finger prints at the scene of a crime were involved in previous crimes. They often try to match the fingerprints of unknown corpses with finger print records to establish their identities. They work in laboratories and offices, and travel to other areas such as crime scenes. Retrieving fingerprints outside may be difficult and require specialized processes, such as dusting glassware, windows, or walls with a fine powder. This powder contrasts with many different surfaces and will highlight any fingerprints that remain. Another method of retrieving fingerprints is to lift them off with a flexible tape, which can be brought back to the laboratory for further evaluation and matching.
Fingerprint classifiers compare new prints against those found after the commission of similar crimes. The classifier documents this information and transfers it to the main record-keeping system, often a large mainframe computer system. In the last decade or so, computers have greatly enhanced the possibility of matching new fingerprints to those already on file. A fingerprint classifier may keep individual files on current crimes and note any similarities between them.
Identification technicians work at various jobs related to maintaining police records. In addition to handling fingerprint records, they also work with other kinds of records, such as police reports and eyewitness information about crimes and accidents. They operate equipment used to microfilm police records, as well as store the microfilm and retrieve or copy records upon the request of police or other public officials. Forensic pathologists perform autopsies to determine the cause of death; autopsies are almost always performed on victims of crime. Forensic psychiatrists also conduct psychiatric evaluations of accused criminals and are often called to testify on whether the accused is mentally fit to stand trial.
Molecular biologists and geneticists analyze and review forensic and paternity samples, provide expert testimony in civil and criminal trials, and identify and develop new technologies for use in human identification.
Other job titles within forensic science include forensic toxicologists, who are concerned with detecting and identifying the presence of poisons or drugs in a victim’s body; forensic odontologists, who use dental records and evidence to identify crime victims and to investigate bite marks; and forensic anthropologists, who examine and identify bones and skeletal remains.
Forensic experts spend the bulk of their time in the laboratory working with physical evidence. They seldom have direct contact with persons involved in actual or suspected crimes or with police investigators except when collecting evidence and reporting findings. Forensic experts do not interpret their findings relative to the criminal investigation in which they are involved; that is the work of police investigators. The purpose of crime lab work is to provide reliable scientific analysis of evidence that can then be used in criminal investigations and, if needed later, in court proceedings.
Almost all jobs in this field require at least a bachelor’s degree. In high school, you can begin to prepare for a career in forensics by taking a heavy concentration of science courses, including chemistry, biology, physiology, and physics. Computer skills are also important, especially for fingerprint classifiers. A basic grounding in spoken and written communications will be useful because forensic experts must write very detailed reports and are sometimes called on to present their findings in court.
Many universities and community colleges in the United States offer programs in forensic science, pathology, and various aspects of crime lab work. These courses are often spread throughout the school, in the anatomy, physiology, chemistry, or biology departments, or they may be grouped together as part of the criminal justice department.
Certification or Licensing
Certification may be an advantage for people working in toxicology and document examination. Specialists in these and other disciplines may also be required to take undergraduate and graduate course work in their areas. In a field such as toxicology, advanced chemistry work is important.
To be successful in this field, you should have an aptitude for scientific investigation, an inquiring and logical mind, and the ability to make precise measurements and observations. Patience and persistence are important qualities, as is a good memory. Forensic experts must constantly bear in mind that the accuracy of their lab investigations can have great consequences for others.
cif-chem-89.jpg A police forensic team investigates a bomb blast site.
A large community police department may have a crime lab of its own whose experts can give you specific information about their work and the preparation that helped them build their careers. Smaller communities often use the lab facilities of a larger city nearby or the state police. A school counselor or a representative of the local police may be able to help you arrange a tour of these labs. Lectures in forensic science given at universities or police conventions may also be open to students. Online services and Internet access may provide entry to forums devoted to forensic science and are good sources of information on the daily and professional experiences of people already active in this field.
Forensic scientists are typically employed by large police departments or state law enforcement agencies nationwide. However, individuals in certain disciplines are often self-employed or work in the private sector. For example, forensic engineers—who use mathematical principles to reconstruct accident scenes, determine the origins of explosions and fires, or review the design of chemical or molecular structures—may be employed by large corporations, small firms, or government agencies. Forensic anthropologists, who identify skeletal remains, may work within a university or college, teaching related courses, conducting research, and consulting on cases submitted by law enforcement agencies. They may also be employed by the military or a medical examiner’s office. Many forensic science concentrations also offer part-time or consulting opportunities, depending on an individual’s level of education and experience.
Crime labs are maintained by the federal government and by state and local governments. Applications should be made directly to the personnel department of the government agency supporting the lab. Civil service appointments usually require applicants to take an examination. Such appointments are usually widely advertised well in advance of the application date. Those working for the FBI or other law enforcement agencies usually undergo background checks, which examine their character, background, previous employers, and family and friends.
In a large crime laboratory, forensic technicians usually advance from an assistant’s position to working independently at one or more special types of analysis. From there they may advance to a position as project leader or being in charge of all aspects of one particular investigation. In smaller labs, one technician may have to fill many roles. With experience, such a technician may progress to more responsible work but receive no advancement in title. Fingerprint classifiers who work for police departments may pursue advancement with a different government agency or apply for positions with the FBI.
Crucial to advancement is further education. Forensic experts need to be familiar with scientific procedures such as gas chromatography, ultraviolet and infrared spectrophotometry, mass spectroscopy, electrophoresis, polarizing microscopy, light microscopy, and conventional and isoelectric focusing; knowledge of these analytical techniques and procedures is taught or more fully explored at the master’s and doctor ate levels. Other, more specific areas of forensics, such as DNA analysis, require advanced degrees in molecular biology and genetics.
Earnings for forensic analysts vary with the employer, geographic location, and educational and skill levels. Salaries for entry-level positions as research assistants or technicians working in local and regional labs range from $20,000 to $25,000. For those individuals with a bachelor’s degree and two to five years of specialized experience, salaries range from $30,000 to $40,000. Salaries for those with advanced degrees range from $50,000 to well over $100,000 a year. The U.S. Department of Labor reports that the median hourly salary for forensic science technicians was $21.79 in 2006. For full-time employment, this means a median salary of approximately $45,330 a year.
Forensic experts usually perform the analytical portion of their work in clean, quiet, air-conditioned laboratories, but they are frequently required to travel to crime scenes to collect evidence or study the site to understand more fully the evidence collected by detectives. When gathering evidence and analyzing it, forensic experts need to be able to concentrate, sometimes in crowded, noisy situations. For this reason, forensic experts must be adaptable and able to work in a variety of environments, including dangerous or unpleasant places.
Many crime scenes are grisly and may be extremely distressing for beginning workers and even for more seasoned professionals. In addition, forensic experts who work with human remains will regularly view corpses, and, more often than not, these corpses will have been mutilated in some way or be in varying degrees of decomposition. Individuals interested in this field need to develop the detachment and objectivity necessary to view corpses and extract specimens for testing and analysis.
Simulating the precise conditions of a crime site for a full analysis is often crucial, so forensic experts often return to the site so that they can perform tests or functions outside of the controlled environment of their lab. When traveling to the scene of a crime, forensic experts may have to carry cases of tools, cameras, and chemicals. In order not to risk contaminating evidence, they must follow strict procedures (both in and Out of the laboratory) for collecting and testing evidence; these procedures can be extremely time-consuming and thus require a great deal of patience. Forensic experts also need to be able to arrive at and present their findings impartially. In large labs, they often work as part of a team under the direction of a senior technologist. They may experience eyestrain and contact with strong chemicals, but little heavy physical work is involved.
The number of forensic experts employed in the United States is expected to grow much faster than the average for all other occupations through 2014, according to the U.S. Department of Labor. Population increases, a rising crime rate, and the greater emphasis on scientific methodology in crime investigation have increased the need for trained experts. Forensic experts who are employed by state public safety departments should experience especially strong employment opportunities, although some government agencies may be under pressure to reduce staff because of budget problems. Forensic experts with a four-year degree in forensic science will enjoy the best employment prospects.
FOR MORE INFORMATION
For information on careers and colleges and universities that offer forensic science programs, contact:
American Academy of Forensic Sciences
410 North 21st Street
Colorado Springs, CO 80904-2798
To learn more about forensic services at the FBI, visit the FBI Laboratory Division’s Web site.
Federal Bureau of Investigation (FBI)
J. Edgar Hoover Building
935 Pennsylvania Avenue, NW
Washington, DC 20535-0001
For additional information on forensics and forensics professionals, contact: the following organizations:
American Society of Questioned Document Examiners
PO Box 18298
Long Beach, CA 90807-8298
Society of Forensic Toxicologists
One MacDonald Center
1 North MacDonald Street, Suite 15
Mesa, AZ 8520 1-7340
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