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What Do Forensic Scientists Do?
Source: AAFS, "So You Want to Be A Forensic Scientist"

The American Academy of Forensic Scientists provides a plethora of resources to students and professionals in the field. Below is information provided by the AAFS on a career in forensic science.

What is Forensic Science?

The word forensic comes from the Latin word forensis: public; to the forum or public discussion; argumentative, rhetorical, belonging to debate or discussion. From there it is a small step to the modern definition of forensic as belonging to, used in or suitable to courts of judicature, or to public discussion or debate. Forensic science is science used in public, in a court or in the justice system. Any science, used for the purposes of the law, is a forensic science.

What Do Forensic Scientists Do?

The forensic sciences form a vital part of the entire justice and regulatory system. Some of the different divisions, or disciplines, of forensic science have become identified primarily with law enforcement — an image enhanced by television and movies. This is misleading because forensic scientists are involved in all aspects of criminal cases, and the results of their work may serve either the defense or the prosecution. The forensic scientist's goal is the evenhanded use of all available information to determine the facts and, subsequently, the truth.

The forensic scientist's role in the civil justice arena is expanding. Issues range from questions of the validity of a signature on a will, to a claim of product liability, to questions of whether a corporation is complying with environmental laws, and the protection of constitutionally guaranteed individual rights.

Forensic science is a rewarding career where the love of science can be applied to the good of society, public health, and public safety.

Work

The work of the forensic scientist may reduce the number of cases entering our overloaded court system by assisting the decision-makers before a case reaches the court. The facts developed by forensic scientists, based on scientific investigation, not circumstantial evidence or the sometimes unreliable testimony of witnesses, may convince prosecuting or defense attorneys, a grand jury, or a judge that an issue does not merit a court hearing.

The work of the forensic scientist at times proves the existence of a crime or makes connections to a crime. The forensic scientist provides information and expert opinion to investigators, attorneys, judges, and juries which is helpful in determining the innocence or guilt of the accused.

The rule of law is based on the belief that the legal process results in justice. This has come under some question in recent years. Of course, the forensic scientist cannot change skepticism and mistrust single-handedly. He can, however, contribute to restoring faith in judicial processes by using science and technology in the search for truth in civil, criminal, and regulatory matters.

The forensic scientist is entirely responsible for the work he performs; no one else can write his report nor testify to his opinion. However, it takes teamwork to solve a crime. Scientists work closely with police officers, sheriff's deputies, prosecuting and defense attorneys, DEA, CIA, and FBI agents, immigration workers, and crime scene investigators, to name a few.

There is a strong requirement for accurate record keeping, chain-of-custody documentation, stringent quality control, and data management. Chain-of-custody guarantees that the integrity of evidence is maintained at all times. The time, date, location, and signature are required when transporting a piece of evidence within the laboratory or to an outside facility.

Ethics

The forensic scientist, no matter where or by whom he is employed, works only for truth. He must make sure that the examination is complete, the tests performed are done correctly, the interpretation of the data is thorough, the written report is correct and easily understood by a non-scientist, and the testimony is complete and truthful. Anything less is not acceptable.

Testimony

Testimony is the verbal statement of a witness, under oath, to the trier of fact, that is, the judge and/or jury. The ordinary witness can testify only on the basis of personal knowledge of a situation gained through the use of his five senses. He may not express opinions formed on any other basis. The forensic scientist, on the other hand, can testify not only on the basis of personal knowledge, but also in the form of opinion based on his informed evaluation of the evidence presented and scientific tests performed and interpreted within the bounds of his skills, experience, and ability. He is an "expert" witness as opposed to an ordinary or "fact" witness.

There are four criteria that are generally required to qualify a person as an expert witness. They are: educational degrees received, number of years of occupational experience in the field, membership in professional organizations, and professional articles or books that the person has published.

The forensic scientist, as an expert witness, must be able to explain complex chemical reactions, the working of scientific instruments, or medical conditions in simple everyday language understandable to anyone, not scientific jargon or "gobbledegook." This is not easy. It is so difficult that before a new scientist is allowed to testify, a mock court is held so the scientist can learn how it feels to testify, and how to convert his hard-earned scientific knowledge into simple terms.

The forensic scientist must be impartial and unbiased. The forensic scientist must tell all of the truth, "the whole truth," no matter what it is or whom it hurts or helps. An expert opinion can be offered only if there are scientific facts upon which to base it.

In court, the work of the forensic scientist is carefully examined to find any flaws, whether in the test performed, the interpretation of the results, or the science upon which opinion is based. Whether the forensic scientist "expert" is hired by the prosecution or defense, the opposing attorney will try to undermine or discredit testimony which is against his client.

The forensic witness must be qualified and knowledgeable of both his special area of scientific knowledge and expertise and the rules of evidence that govern the admissibility of opinions and conclusions.

The forensic scientist often spends long hours testifying clearly and concisely in judicial proceedings concerning scientific information and what it means. Throughout he must maintain a posture of impartial professionalism.

"If the law has made you a witness, remain a man of science.
You have no victim to avenge, no guilty or innocent person to convict
or save — you must bear testimony within the limits of science."'

— Dr. P.C.H. Brouardel
19th Century French Medico-legalist