In the early 1900s, a German professor of jurisprudence, Franz von Lizst, staged an argument between two students in a class he was teaching. Voices were raised, a gun was drawn, and a shot was fired. When their classmates were later asked to give an account of the altercation, many of them got substantial facts wrong. The point von Lizst was trying to make was that eyewitness testimony is often erroneous and should not always be trusted. In the century that has elapsed since then, the point has been demonstrated time and time again, but with far more tragic consequences than in the German classroom. Many people convicted on the basis of eyewitness testimony were later proved innocent by scientific evidence. Fortunately for the many remaining innocents serving lengthy sentences in prison or on death row, the powerful tools of forensic science may yet come to the rescue. The now famous Innocence Project at the Benjamin N. Cardozo School of Law at New York has brought about the release of more than 30 convicts by the use of DNA evidence, and promises to exonerate still more victims of the judicial system as the project spreads to law schools around the country.

Forensic science - which is defined as science as applied to legal matters - is most often associated with murder cases, thanks to television programs such as CSI: Crime Scene Investigation and The Profiler. It is often, however, also used to settle nonviolent criminal or civil cases. The expertise of forensic scientists has been required for such wide-ranging situations as determining the cause of a building collapse, finding the source of a pollutant in a community's water supply, or snaring computer hackers who can wreak havoc on air traffic control systems or national power grids. Forensic scientists are also involved in matching the remains of unidentified military personnel with those known to be missing in action (MIAs) and collecting evidence to be used in trials of those accused of war crimes. In 1999, the FBI sent a team of 65 forensic scientists to the former Yugoslavia to collect evidence to be used before the International Criminal Tribunal in the trial of ex-president Slobodan Milosevic.

Because forensic science encompasses such a broad array of technologies, its practitioners typically specialize and become expert in analyzing only certain types of information. For example, testimony from an expert in blood-spatter patterns contributed to the 1966 acquittal of Sam Sheppard, the Cleveland, Ohio doctor accused of murdering his wife. (The case became the basis for The Fugitive movie and series). Other forensic specialists are expert in identifying forged documents, in pinpointing the weapon used in a crime from bullets found at the scene, or in determining how a fire may have started. Still others, forensic toxicologists, can detect drugs and poisons in bodily fluids and identify causes of death. However, many toxicologists, rather than working on cases involving fatalities, carry out functions such as workplace drug screening or measuring alcohol levels in those involved in automobile accidents.

Today, one of the best known areas of forensic specialization (and one that offers many employment opportunities) is DNA profiling, in which bodily fluids taken from a crime scene or victim can be used to implicate or exonerate a suspect. First used in the mid-1980s, DNA profiling has been refined to the point where a given sample can be linked to an individual beyond any doubt whatsoever (with the exception of identical twins). The weak link remains, as was so infamously demonstrated by the O.J. Simpson trial, in the handling of evidence. The current effort by the FBI to create CODIS (Combined DNA Index System), a national database of DNA profiles from convicted offenders, is putting DNA analysts in great demand. Other lesser known specialties include forensic odontology, which involves, among other things, identifying bodies using dental records, and forensic psychology, often used to create a psychological profile of a serial killer or rapist.

So how does one become a forensic scientist? Although many of those who now work as forensic scientists do not have forensic science degrees, a number of programs exist across the United States and are becoming increasingly popular. Among the most well-known are those at the University of Illinois at Chicago, the University of Alabama at Birmingham, Michigan State University in East Lansing, the University of New Haven, the John Jay College of Criminal Justice at New York, and George Washington University in Washington, D.C. Most of these offer both undergraduate and graduate degrees in forensics, but it is common, and some say preferable, to begin with an undergraduate degree in one of the basic sciences, such as chemistry or biochemistry, and subsequently to enter a master's degree program in forensics. Because forensics covers so many different areas, an undergraduate degree in forensics alone is unlikely to provide the specialized training needed on the job. For example, according to David Foran of George Washington University, "a DNA lab would prefer someone with a better DNA background than you're probably going to get from an undergraduate forensics degree." All degree programs typically include some chemistry, biology, biochemistry, and criminal law courses.

Once they enter the work force, most forensic scientists work in lab settings of one kind or another. Most work in the public sector in labs associated with federal, state, or local governments, but some also work for private labs, such as Cellmark Diagnostics in Germantown, Maryland. Another significant fraction of forensic scientists work alongside police officers in what is broadly termed crime scene investigation, but includes many subspecialties. Many students apply to forensic science programs intending to become crime scene investigators, but David Foran cautions that in many cities and counties, police officers themselves analyze crime scenes and collect the evidence. In these areas, one would need to be a police officer before becoming a crime scene investigator. Starting salaries for forensic scientists typically range from $25,000 to $35,000, with the higher salaries associated with federal or private labs.

What draws people to the field of forensic science? Robert Gaensslen of the University of Illinois at Chicago answers in a word: "Television!" Programs such as CSI: Crime Scene Investigation have attracted attention to the profession and increased the number of applicants to schools around the country. Gaensslen stresses that these programs present a fictional rendition of the profession and that a certain amount of 'reality therapy' is necessary to avoid unrealistic career expectations in beginning students. Others say that forensic science offers the opportunity to join a love for science with the ability to solve social problems. Rebekah Gundry, a student at George Washington University, likes the ever-evolving nature of forensic science and the intellectual challenge it brings. In addition, she says, "I've always loved a good mystery!" Kristin Koch, a DNA analyst at Cellmark, likes the excitement of her job, but when asked about the downsides, says it can be stressful and demanding. She adds that it is a job that needs to be taken very seriously. "The work we do can ultimately determine the fate of another human being," she says.

So if you're looking for an off-the-beaten-track career, love science and being able to apply it to concrete problems, and have a penchant for mystery novels, put on your sleuthing cap - forensic science might just be for you!