Criminalistics – Concept, principles, methods and career

We explain what criminology is, its principles and research methods. Also, differences with criminology.

What is criminology?

Criminology it is a discipline that studies and investigates crime, that is, the crime, applying scientific methods and knowledge that allow it to reconstruct the way it was committed, identify the culprits, and explain with great certainty what happened. Together with criminology and other similar disciplines, it constitutes what is known as forensic science.

Criminalistics is often understood as an auxiliary discipline of criminal law or even law in general. It has been defined as the “science of small details”, since focuses on investigative details to find the truth of the crime committed (that is, faithfully rebuild your circumstances).

Although it is an autonomous discipline, it is common for it to draw on practices and knowledge from the natural sciences and many other technical disciplines. As a formal field of study, criminology was born around the seventeenth century, by the hand of forensic medicine, since doctors began to assist in the investigation of cases of homicide or physical violence, contributing their specialized knowledge.

At that time, there was already legal medicine, created in 1575 to assist in the resolution of legal conflicts through medical knowledge, and fingerprints, which emerged around 1665, which is the study of the impressions left by fingerprints. Hand in hand with criminology, many of these disciplines flourished and contributed vital knowledge for the understanding and resolution of crime.

Key to this was the incorporation, during the nineteenth century, of famous criminals to the ranks of the police in Europe, as was the case of the famous Eugene-Francois Vidocq (1775-1857). The latter was the first to propose ballistics studies to solve a homicide, and the first to use molds to capture fingerprints at the crime scene.

However, the most prominent criminalist of all time was the Austrian Hans Gross (1847-1915), who is considered to be the father of this discipline, and founder of a scientific method known as the “Graz criminological school”, since he was also a founding member in 1912 of the Royal and Imperial Institute of Criminology of the University of Graz, in Austria.

Principles of criminology

Criminalistics studies crime from a scientific perspective, that is, methodical, verifiable and concrete, free from speculation and subjectivities, and committed to physical and tangible evidence. To do this, it is guided by a set of principles, that is, fundamental approaches, among which the following stand out:

• Principle of use. Every crime is committed using some physical, chemical, biological or computer agent, which can then be used as evidence.
• Exchange principle. At the time of committing a crime, the criminal, the victim and the scene of the events exchange recoverable and verifiable indications or evidence.
• Correspondence principle. Any footprint, mark or scar necessarily corresponds to the body or object of greater hardness that caused it.
• Principle of certainty. All evidence of any kind that is found at the crime scene deserves a detailed scientific study to determine whether or not it corresponds to the fact under investigation, in such a way that the highest possible levels of certainty are always aspired to.
• Production principle. Every criminal act produces salvageable evidence, since there is no perfect crime. This evidence will depend on the type of crime and the morphology of the place where it is committed.

On the other hand, the criminal process, that is, the method of scientific investigation of crimes, responds to its own fundamental principles, such as:

• Protection of the crime scene, to prevent the evidence from being stolen, modified or new evidence capable of distorting the process from being incorporated.
• Observation of the scene, because in it the necessary evidences will be found to start the investigation.
• Fixing the crime scene, that is, once the evidence has been observed, it must be properly recorded through a written description, photography, planimetry, and so on. Time plays against the truth.
• The lifting of the evidence, which must be done properly so as not to destroy or alter the evidence.
• The study of clues in the laboratory, in order to apply experimental scientific practices and obtain more specialized evidence from them.
• Chain of custody, in charge of verifying that the collection, transport, handling and preservation of the evidence is adequate so as not to vitiate the conclusions drawn from it.
• The preparation of an expert report, that is, the delivery of the scientific conclusions obtained to the pertinent authorities.

Research Methods

Criminalistics employs a multitude of scientific investigative methods and techniques, in order to collect as much data, information and evidence from crime scenes as possible. These methods include:

• Forensic medicine, which consists of the anatomical and physiological study of the corpse or the body of the victim, to extract from it the pertinent medical or biological evidence.
• Forensic meteorology, which consists of the study of the meteorological conditions at the time of the crime, to trace its evidence in the objects involved.
• Forensic genetics, which consists of the collection and comparison of genetic material between the crime scene and the possible suspects. It is of particular use in cases of sexual crime, since there are useful DNA samples in secretions such as saliva, semen, blood, etc.
• Forensic ballistics, which consists of the study of cartridges, bullets and weapons, as well as the crime scene, to check if a weapon was involved in a crime or not, and follow the trajectory of the bullets fired.
• Forensic anthropology, which consists of the recomposition of traits, sex, height, ethnic group and other bodily factors from human remains found.
• Fingerprint, which consists of the collection and collation of fingerprints at the crime scene, to determine if a person held a weapon, was in a place or touched the body of the victim.
• Forensic entomology, which consists of the study of insects and arthropods that lodge in a corpse in both urban and rural environments, in order to determine how long it was exposed to the elements and other circumstantial factors of the crime.
• Forensic toxicology, which consists of the search for foreign substances or stimulants (alcohol, drugs, chemicals, etc.) in the body of the subjects involved, living or dead.
• Piloscopy, which consists of the scientific study of hair or hair found at the crime scene, to determine whether it is of animal or human origin, and whether or not it belongs to a specific person.

Criminalistics career

The career of criminology has a worldwide presence in numerous universities and institutes of forensic sciences. Often taught as a bachelor’s degree, although there are also smaller technical approaches.

Those who graduate from this career are known as criminologists and often find employment in state judicial institutions, in private investigation centers, in NGOs and other international justice organizations, or even in educational institutions in the area.

Criminalistics and criminology

We must not confuse these two disciplines, which although they address the same object of study: crime, they do so from points of view and with very different objectives.

Criminology focuses on revealing how the crime occurred, that is, on recomposing what happened through the investigation. Secondly, criminology studies crime from a philosophical point of view, trying to find the reason for the crimes that happen. We can think of this difference as that the first is a practical, applied discipline, while the second is a theoretical, reflective discipline.