What is Forensic Science? | Applications & Sub-Disciplines | Specialization

Forensic science as a discipline has utilized the knowledge of natural science; it includes many scientific sub-disciplines such as biological science, chemical and toxicological science, and physical science and ballistics to recognize a piece of evidence and utilize it for conviction in the court of law.

The term forensic has been derived from the Latin word forensis, which means a discussion or debate in public. As a discipline forensic science refers to the application of scientific methods and procedures to solve and prove that a crime has taken place.

Forensic Science

Criminalistics is the synonymous term for forensic science which is commonly used in the USA. Forensic science can be broadly defined as the scientific discipline which is related to the recognition, identification, and analysis of physical pieces of evidence by application of methods of natural science for justice.

Historical Perspective

In the 19th century, the utilization of natural science in the criminal justice system began. Sir Arthur Conan Doyle popularized a fictional character, Sherlock Holmes, through his writings.

The character became popular due to the application of scientific crime detection method in solving a crime. In the early part of the 19th century, Mathieu Orfila in Paris proposed scientific methods for the detection of poisons. In 1879, Alphonse Bertillon of France evolved a scientific system for personal identification.

He developed the science of Anthropometry, in which he took the help of many-body measurements which could help in individualizing a person. In 1892, Francis Galton in the UK, wrote a book “Fingerprints” in which he explained about the uniqueness of fingerprints among individuals can be useful in establishing identity.

Hans Gross in 1893, published a classical book named “Handbuch fur Untersuchnugsrichter,” in which he developed principles of the criminal investigation. Edmond Locard of France established a police laboratory in Lyons in 1910; he later proposed a “principle of mutual exchange” according to which every contact leaves a trace. It forms the basis of the criminal investigation.

Dr Leone Lattes of Italy in 1915, utilized Karl Landsteiner’s method of blood group identification on dried bloodstains. He adopted this technique for identifying the blood type of dried blood stains obtained from the scene of the crime.

Albert Osborn in 1910, wrote a book “Question Documents,” which includes principles and methodologies used in the examination of documents whose identity is in dispute.

Calvin Goddard was a US Army Colonel; he developed a comparison microscope in 1920 for comparison of bullets and cartridge cases obtained from the crime scene and those which were received after test firing.

Forensic Science

Applications Of Forensic Science

Forensic science as a discipline has utilized the knowledge of natural science; it includes many scientific sub-disciplines such as biological science, chemical and toxicological science, and physical science and ballistics to recognize a piece of evidence and utilize it for conviction in the court of law.

Forensic science is applied for the following purposes:

  • Securing and recording the scene of the crime.
  • Collection and preservation of potential pieces of evidence.
  • Establishing the identity of the criminal and victim.
  • Production of valid expert testimony to prove a crime has taken place.

Sub-Disciplines Of Forensic Science

A brief description of fields/sub-discipline of forensic science and their application in the criminal justice system is as follows:

  • Forensic Biology: It deals with the examination, identification, and evaluation of biological shreds of evidence obtained either from human, animal, plant and microbial sources such as blood, semen, sweat, saliva, tears, milk, hair, faecal matter, vegetable shreds of evidence( flowers, leaves, fruits, pollen) diatoms and fibres. It also deals with the analysis of DNA and protein analysis to clarify paternity disputes.
  • Forensic Chemistry: It deals with the identification of chemical shreds of evidence such as petroleum products like petrol, kerosene and diesel, construction material such as cement, and concrete, pesticides and insecticides, analysis of narcotics and other drugs such as heroin, cocaine, opium derivatives, etc., cosmetics, natural and synthetic fibres.
  • Forensic Toxicology: It is a sub-branch of forensic chemistry. It deals with the examination and analysis of viscera, vomit, stomach wash to identify the origin of poison or any other toxic agent.
  • Forensic Physics: It deals with the identification of physical pieces of evidence such as glass, paints, fibres, wires, ropes, soil, dust, and metal fragments.
  • Forensic Ballistics: It is a sub-branch of forensic physics. It deals with the examination of firearms and their projectiles such as bullets, slugs, balls, pellets, and cartridge cases obtained from the scene of a crime.
  • Forensic Document Examination: It deals with the comparison of the unknown document sample (handwritten, printed document) with the requested specimens to establish the identity of an author. It also involves the examination of the typewriter or any other machinery used to develop the document, the defect in its keys, make, and model. The examination of rubber stamps, alteration of the writing by chemical and natural erasers and analysis of inks, papers, pen, pencil, and other writing instruments is done under the discipline of question document examination. This discipline also deals with forged tickets and counterfeited currencies.
  • Forensic Medicine: It applies the knowledge of medical science in establishing the cause of death, the manner of death, and time since death in suspicious death cases. It involves procedures of detail internal and external examination of the body including detailed autopsy.
  • Forensic Entomology: It deals with the examination of the partially decayed dead victim including the collection and analysis of the life cycle of insects which can help in establishing the time since death, and cause of death.
  • Forensic Psychology: It applies the knowledge of psychology to know the intention of the criminal behind the crime and to prove that the mental condition of the offender was sound enough while committing the crime.
  • Forensic Photography: It deals with the application of photographic techniques to capture the scene of the crime as a record, comparison of inks in the documents, and impressions on bullets and cartridge cases.
  • Forensic fingerprints and other impressions: It deals with the identification, collection, and comparison of fingerprints, sole and palm prints, ear and rug prints obtain from the scene of the crime with those received from suspects.
  • Forensic Dentistry: It utilizes the fields of dentistry in establishing the age of the victim or criminal by examining the denture either in living beings or in the dead carcass, and bite marks analysis.
  • Forensic Anthropology: It follows the principles of Alphonse Bertillon’s system of personal identification. It involves the study of body measurements of living beings in establishing the identity of criminals, and victims help in cases of impersonation.

Forensic Scientist: Education and Job Description

A forensic scientist generally performs two important tasks that are, analyzing the pieces of evidence and testify them in court. The crime scene investigators collect the shreds of evidence and transport them to the crime lab. A forensic scientist has to follow specific laboratory standards while performing tests on the acquired samples.

They are trained to use and provide a valuable report on the examination of even minute available samples. Such scientists when present their report in court they use non-specialist as well as specific terms to make the justice system understand the results of the analytical procedures.

Educational Requirements To Become A Forensic Science Expert

With the increase in acceptance and demand for various forensic experts in the court of law, the specializing fields in the forensic sciences are gaining momentum. 

The specialization of experts varies from the collection of pieces of evidence to the proving of opinion related to the evidence in the criminal justice system. A chain of custody is needed to be maintained by the experts while handling the potent evidence. Thereby, the forensic science discipline requires a team of knowledgeable, and skilled professionals.

Here, are some examples of forensic scientists in specialized fields and the educational requirements associated with their careers.

  • Crime Scene Investigators:

A crime scene investigator can be a police official. But a bachelor’s degree in any of the basic sciences like physics, chemistry and biology and a basic or advanced certificate in crime scene investigation can help a person to become a crime scene investigator.

An expert in this field must have thorough knowledge and skill of collection, handling, and packaging of evidence. CSI must have knowledge of documenting the scene of a crime by photography, videography, sketching, and note-making.

All these procedures are required to make a record of the observations at the scene of the crime. Such an expert can be summoned by the court to give his testimony as an expert witness to provide and present an overview of his observations at the scene of the crime.

  • Crime Lab Forensic Professionals:

There is a hierarchy in the crime lab which is followed according to the skill and qualification of the forensic professionals. At the lower level, there are forensic science lab technicians these professionals are educated with a bachelor’s degree in basic science like physics, chemistry, biology, and forensic science.

They may have experience working in basic science labs. A master or postgraduate degree in forensic science is not required to become a forensic lab technician. Such professionals help scientific officers in routine lab procedures.

Scientific officers are masters or PhD degree holder professional either in basic sciences or forensic science. They have relevant research experience in forensic science. The analytical report prepared under the supervision of these experts is accepted in the court. They can also attend the court to present their analytical reports called testimony.

  • Forensic Pathologists:

To become a forensic pathologist one must have a bachelor’s degree in medical science. A specialized master’s degree in forensic medicine is required from the medical college.

Such experts are called upon to determine the time scene of death and the manner of death at the scene of the crime. These experts are medical practitioners who perform autopsies (post-mortem) of dead bodies on a daily basis.

  • Forensic Anthropologists:

Forensic anthropologists are scientists possessing a degree in anthropology at the bachelor’s, masters, and doctoral levels. The discipline of anthropology at all educational levels exhibit some portions of the application of anthropology for forensic science.

The forensic anthropologist must know the techniques for collection, handling, and preservation of the bones and other relevant human remains as teeth, hair, skin tissues found buried under the heap of the soil.

  • Forensic Odontologists:

These professionals are dentists. They are educated in the field of dentistry at the bachelor’s level and forensic dentistry at the masters level. They are trained to conduct postmortem dental examinations, x-rays report comparison with the denture of the suspect or victim in cases of impersonation, comparison of the bite marks with the denture of the suspects, linking the obtained tooth with the source denture and dental pulp DNA analysis.

  • Forensic Document Examiner:

A forensic document examiner or question document examiner is a forensic scientist who is holding a degree in chemistry or forensic science at the bachelor’s level and a degree in forensic science at the masters and doctoral level.

A knowledge of chemistry is required because some techniques such as deciphering the handwriting from an erased and burned documents require specific chemical techniques. These experts are trained in handwriting comparison and determining the source of typed and printed materials.

  • Forensic Fingerprint Examiner:

A forensic fingerprint examiner is a forensic scientist who exhibits a degree of forensic science at the bachelor, master and doctoral level. But may hold a degree in chemistry or biological science at the bachelor’s level.

An expert in this field is capable of matching either manually or using automated technology the fingerprints obtained at the scene of the crime with those acquired from the suspects.

  • Forensic Biology Expert:

They are qualified in biological sciences such as zoology, botany, or genetics at the bachelor level and should have a master’s degree in forensic science or the same bachelors level discipline. They may acquire a specialized certificate, diploma, doctoral degree in forensic biology.

A Forensic biology expert is trained in handling, collection, packaging, laboratory analytical procedures, and preparation of expert testimony for biological pieces of evidence such as blood, semen, sweat, saliva, faeces, tears, milk, hair, vegetable fibres, and tissues.

These experts are trained in specialized DNA technology which allows paternity testing, establishing the identity of the deceased and in cases of impersonation.

  • Forensic Ballistic Expert:

Such an expert should be holding a degree in physics at the bachelor’s and master’s level or may have a degree in forensic science at the masters and doctoral levels. As the physics discipline will provide a strong foundation of basic laboratory techniques, it will help in solving the distance and trajectory followed by a bullet or any other projectile from the tile it expelled out of the projectile till it hit the target. These experts also handle bomb and nuclear explosion cases.

Such an expert exhibits a degree of chemistry, biochemistry, toxicology at the bachelor’s, masters, and doctoral level. These are forensic scientists who can give their opinion after examining an unknown substance such as drugs, medicine, or poison.

  • Forensic Physics Expert:

Such an expert should be holding a degree in physics at the bachelor’s, master’s level, or may possess a degree of forensic science at the masters and doctoral level.

The expert must know the procedure of collection, handling, preservation, and examination of physical evidence such as soil, glass, paint, tool marks, electrical wires, tire and skid marks obtain at the scene of a crime.

  • Cyber Forensic Scientists:

Such an expert must have a degree in computer science at the bachelor’s, master’s, and doctoral levels. The expert must know the procedure to secure the cybercrime scene, collection, and handling of hardware and software evidence such as computer systems, laptops, smartphones, floppies, CDs, pen drives, electronic programs, emails, and messages.

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