Forensic science is the scientific method of gathering and examining information about the past which is then used in a court of law. The word forensic comes from the Latin forēnsis, meaning "of or before the forum." In Roman times, a criminal charge meant presenting the case before a group of public individuals in the forum. Both the person accused of the crime and the accuser would give speeches based on their sides of the story. The case would be decided in favor of the individual with the best argument and delivery. This origin is the source of the two modern usages of the word forensic – as a form of legal evidence and as a category of public presentation. In modern use, the term forensics in the place of forensic science can be considered correct, as the term forensic is effectively a synonym for legal or related to courts. However, the term is now so closely associated with the scientific field that many dictionaries include the meaning that equates the word forensics with forensic science.
Because the work of a forensic scientist is intended to be used in court and because scientific evidence can be very powerful, the forensic scientist must be accurate, methodical, detailed, and above all, unbiased. The ability to keep detailed notes and to write clear, concise, and accurate reports is vital.
The forensic scientist must be able to determine which facts or items of evidence are relevant. In most cases, that’s easy – the item or items are provided to the forensic scientist for examination and analysis. In other cases, the forensic scientist may need (or want) to personally go to the scene to conduct an on-site analysis, gather evidence, or document facts for later analysis. Having been provided or having gathered the relevant information, the forensic scientist then has to decide which examinations, tests, or analyses are appropriate – and relevant – to the issue(s) in dispute. (Is that powder cocaine or not? Did a defect in the road surface cause the crash?). Then, the forensic scientist must conduct the most appropriate tests/analyses and document the process. Afterward, the forensic scientist must interpret the results and write a clear, concise report documenting the steps followed to reach this conclusion or opinion of the forensic scientist.
The forensic scientist will, at some point, have to testify. Testimony is the verbal statement of a witness, under oath, to the judge or jury. Forensic scientists are “expert” witnesses as opposed to ordinary or “fact” witnesses. Expert witnesses are permitted to testify not just about what the results of testing or analysis were (“facts”), but also to give an opinion about what those results mean. For example, a forensic scientist may testify about the observed, factual results of a chemical drug analysis and that, in their expert opinion, the results show that the tested substance is a specific drug, such as cocaine or heroin.
To qualify as an expert witness, the forensic scientist must have a solid, documented background of education, training, and experience in the scientific discipline used to conduct the examinations, testing, or analyses about which the forensic scientist wants to testify.
Sometimes in court, the work or qualifications of the forensic scientist are challenged. A party to a court case may challenge whether the scientist performed the tests correctly; whether the scientist interpreted the results accurately; or, whether the underlying science is valid and reliable. Finally, a party to a court case may challenge whether the scientist is properly qualified to render an expert opinion or question the scientist’s impartiality.
“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
The word forensic comes from the Latin word forensis. A relevant, modern definition of forensic is: relating to, used in, or suitable to a court of law (Merriam Webster Dictionary, www.merriam-webster.com). Any science used for the purposes of the law is a forensic science.
The forensic sciences are used around the world to resolve civil disputes, to justly enforce criminal laws and government regulations, and to protect public health. Forensic scientists may be involved anytime an objective, scientific analysis is needed to find the truth and to seek justice in a legal proceeding. Early on, forensic science became identified with law enforcement and the prosecution of criminal cases — an image enhanced by books, television, and movies. This is misleading because forensic science is objective, unbiased, and applies equally to either side of any criminal, civil, or other legal matter.
Forensic science is a rewarding career where the love of science can be applied to the good of society, public health, and public safety.
What Forensic Science Technicians Do
Forensic science technicians help investigate crimes by collecting and analyzing physical evidence. Many technicians specialize in either crime scene investigation or laboratory analysis. Most forensic science technicians spend some time writing reports.
At crime scenes, forensic science technicians typically do the following:
- Analyze crime scenes to determine what and how evidence should be collected
- Take photographs of the crime scene and evidence
- Make sketches of the crime scene
- Record observations and findings, such as the location and position of evidence
- Collect physical evidence, including weapons, fingerprints, and bodily fluids
- Catalog and preserve evidence for transfer to crime labs
- In laboratories, forensic science technicians typically do the following:
- Perform chemical, biological, and physical analysis on evidence taken from crime scenes
- Explore possible links between suspects and criminal activity using the results of scientific analyses
- Consult with experts in related or specialized fields, such as toxicology (the study of poisons and their effect on the body) and odontology (a branch of forensic medicine that concentrates on teeth)
- Reconstruct crime scenes
Forensic science technicians may either be generalists who perform all or many of the duties listed above, or they may specialize in certain techniques and sciences. Generalist forensic science technicians, sometimes called criminalists, perform the duties of crime scene investigators and laboratory analysts. They collect evidence at the scene of a crime and perform scientific and technical analysis in laboratories or offices.
Forensic science technicians who work primarily in laboratories may specialize in the natural sciences or engineering. Specialists typically apply their knowledge to the investigation of criminal cases rather than scientific enquiry. Those who work in laboratories, such as forensic pathologists and latent print examiners, typically use chemicals and laboratory equipment such as microscopes when analyzing evidence. They also may use computers to examine fingerprints, DNA, and other evidence collected at crime scenes. They often work to match evidence to people or other known elements, such as vehicles or weapons. Most forensic science technicians who perform laboratory analysis specialize in a specific type of evidence analysis, such as DNA or ballistics.
Some forensic science technicians, called forensic computer examiners or digital forensics analysts, specialize in computer-based crimes. They collect data and analyze it to uncover and prosecute electronic fraud, scams, or identity theft. Because of the increased popularity of personal computing, digital data is often used to help solve non-cyber crimes. Computer forensics technicians must adhere to the same strict standards of evidence gathering found in general forensic science because the need to maintain evidence integrity is still critical.
All forensic science technicians prepare written reports that detail their findings and investigative methods. They must be able to explain their reports to lawyers, detectives, and other law enforcement officials. In addition, forensic science technicians may be called to testify in court about their findings and methods.