Forensic identification is one way to establish the truth in the investigation of crimes. It involves the study and comparison of the object with its images, presented in the form of "ideal" and materially fixed traces left by the attacker or arising from the commission of illegal actions by him. Let us further consider the objects, types and forms of forensic identification .
General information
Legal relations associated with identification arise when:
1. Research methods.
2. The subjects performing the study of subjects.
3. Objects of forensic identification .
Classification
Criminal identification is divided depending on the legal nature into:
- Procedural. In this case, the concept and objects of forensic identification are regulated by the CPC.
- Non-procedural. Such identification is carried out in the course of operational-search activities, in the formation of forensic records.
Identification is classified by subject. The objects of forensic identification are studied:
- The investigator.
- Operational employee.
- By a specialist.
- By an expert.
- Court.
- The prosecutor.
Depending on the display method, the identification is divided into matching by:
- Materially fixed mappings of the properties and attributes of forensic identification objects.
- A mental image fixed in a person’s memory. It is in particular about identification during identification.
Another classification criterion is the probative value of identification. She may be:
- Individualized. In this case, there is a close interaction of the subject and the object of forensic identification . An authorized employee shall determine whether the recorded trace belongs to a specific person. The establishment of the object of forensic identification occurs by comparing the traces of the hands, smell, blood, hair, other biological objects.
- Group. In this case, the possible connection with the event is determined by the properties of the objects of forensic identification . In the course of research establish the type, class, gender, group of the object. For example, it was determined that the tracks left by the wheels at the scene of the accident were left by a GAZ-3113 car.
Identification can be carried out according to general criteria, i.e., an entire object is established for some part of it. For example, pieces of a document, a detail of a mechanism, etc., are studied.
The basis for conclusions
When using existing types of forensic identification, both objects and their parts are compared according to relatively stable characteristics. They are divided into:
- Private As a rule, they are the elements of the object formed during the repair, production, use, elements of the pattern of the finger of a human hand, etc.
- Are common. They are inherent in homogeneous objects. Their presence allows you to attribute the object to a specific group (for example, to determine the blood group).
Stages and Tasks
The objects of forensic identification are classified into identifiable and identifying. The first ones include:
- Items.
- People.
- Animals.
- Substances.
- Weapons
- Vehicles.
- Instruments.
The second group contains objects containing mappings of the studied traces. This, in particular, is about signs of appearance, a combination of skills in handwriting, footprints, teeth, hands, blood, etc.
Above we examined the most common classification of forensic identification by forms and objects. In this case, regardless of the specific method of research and comparison of traces, the process includes 4 stages:
- Inspection In the course of such a survey, all types of forensic identification objects and their elements are studied. In addition, samples are studied (experimental, free and conditionally free).
- A detailed study of the object of forensic identification . Its task is to identify the maximum number of private and common features. An experiment may be conducted at this stage. For example, the experimental extraction of bullets and shells from weapons.
- Comparison of identified signs. At this stage, matching and differing properties are established.
- Assessment of signs and drawing conclusions about the absence or presence of identity. They can be negative or affirmative, probable or reliable.
Group and individual identity
The establishment of group identification, acting as the stage of research, is considered an integral stage of individual comparison. Moreover, this procedure may be an independent type of research.
In group study, identity is established, not similarity. This is due to the fact that the similarity between the objects of forensic identification cannot be considered sufficient to formulate a conclusion about the belonging of the tracks to a specific group.
More significant for the investigation is individual identification. But the definition of group identity can perform no less important tasks, since it can significantly narrow the list of compared objects and can serve as the basis for terminating their comparative study.
Determining the source of origin
This technique was developed to minimize the volume of classification groups, which may include objects of forensic identification .
In the course of such a study, the ownership of the traces being compared to one mass (buckshot, shot, ink in a pen and strokes, etc.), a group, a batch of products (usually mass consumption) produced by a particular enterprise is established. In some cases, the workshop, machine tool, product release date, work shift, etc. are determined. A comparative study is also carried out in relation to the internal characteristics of the object, its structure, composition, and traces that reflect the course of its creation, characterizing the tools and mechanisms used in production.
Exploration of the whole object in parts
Depending on the initial information, the study can be carried out according to a materially fixed display, in a mental image, in parts of the whole object of forensic identification .
In the latter case, the individual elements of the damaged item are compared. These can be fragments, debris, scraps of paper, parts, units, etc. The study is carried out along the separation lines, the microrelief of the combined elements, the signs of the structure, and physicochemical properties.
A variation of this identification is the study of volume, capacity, storage by comparing the contents with traces of liquid, bulk and other substances and their parts found at the crime scene. For example, investigators need to establish that the kerosene found at the scene of the fire was taken from a canister seized from a suspect during a search. For identification, it is necessary that the case file contains a container found in the suspect, and reliable information that the liquid was in it, and that there were no other stores.
In a comparative study, the nature of features of objects is of particular importance. Depending on them, identification is carried out by:
- The external structure.
- Odor features.
- The internal structure.
- Functional and dynamic features.
Subjective sign
Depending on the subject and nature of the procedural regulation, judicial, expert and investigative identification is distinguished.
The latter is carried out by an authorized employee - the investigator - in the course of the implementation of procedural actions. For example, identification is carried out upon presentation of objects for identification, comparison of detected and seized items during seizure, search, inspection. Investigative identification is distinguished by the fact that in solving the tasks, special knowledge is not required.
Expert research is carried out by persons with special knowledge and skills.
Identification can be carried out during the trial. Comparison is made by direct perception of objects or by means of proof.
Groups of objects
The objects of forensic identification can be very different. All of them are grouped:
- Living people.
- The corpses.
- Land plots.
- Animals, objects and things.
- Transport.
Depending on the branch of forensic science, to which the objects being compared belong, identification is distinguished:
- Trasological.
- Forensic ballistic.
- Fingerprint.
- Handwriting, etc.
Additional categories
The objects of inanimate and living nature and their elements were indicated above. However, forensic identification is also performed in relation to a special group of objects that are associated with the matching technique. They perform various tasks in the research process. This group includes objects and their samples:
- By which identity is established.
- Showing traces by which identification occurs.
Until objects are identified, they are referred to as sought, i.e. identifiable. Traces found at the crime scene are verifiable. Moreover, their number may be large. Among the traces being checked, the desired object may not be.
Identifiers include objects that contain source material, without which identification cannot be carried out. In one such object, heterogeneous signs (properties) of different objects may be present. For example, the manuscript displays signs of handwriting. According to them, the person who wrote it is established. At the same time, the manuscript contains signs by which the author of the text can be identified. These faces may not match.
Comparative samples
They form a relatively independent group of identification objects. In this case, the samples are not required elements of the study. The need for them arises when it is impossible or significant difficulties in comparing identifiable and identifying objects. For example, the determination of weapons in the wake of the barrel channels in the pool is impossible without comparing them with the wake in the pool obtained during the experimental shot. Direct comparison of the traces and grooves of the bore in the pool is not possible.
Samples in a group study of substances, materials, products are their samples. At the same time, they can be only those parts that undoubtedly display the features of the objects being checked, as well as their media containing the necessary amount of features and comparable with identifying objects.
Sample Classification
Trial instances of objects vary depending on the conditions and method of preparation. Samples can be experimental and free. The latter are objects that arose not in connection with the crime and the investigation. They relate, as a rule, to the period preceding the operational-search measures. Such samples are considered the most valuable.
Experimental specimens are obtained specially during the investigation from the victim, suspect, witness, accused. For example, a person writes a text dictated by an investigator or at the request of an employee; the expert carries out experimental shooting from weapons, etc.
Identification tag
Each object investigated in forensics is endowed with a huge number of properties and characteristics. For identification, however, not all of its features are used, but only those that are displayed in the trace of an object of interest to the investigation.
For example, to identify the person who wrote the text, only the handwriting features reflected in this manuscript can be used. Other attributes are already used to determine the author of the text. In particular, the properties of speech displayed in the text are studied.
Identification features can be the external features of an object: shape, size, appearance, relief, etc. They can also be features of the internal structure: density, anatomical features, hardness, etc.
Terms of Use
In forensics, certain requirements apply to the attributes of objects:
- Specificity and materiality. Such requirements, as a rule, correspond to properties that may not reflect the essential features of objects, but are atypical, brightly individual. Accordingly, they are recognized as the most significant in identification. For example, such signs are deviations in handwriting, special external signs of a person, etc. The more peculiar the sign, the higher the identification significance.
- Sustainability. Its criteria are recognized as the constant reproducibility of the sign or its repeatability in different conditions in combination with uniquely transmitted information. A slight variability of the characteristic within the identification period is allowed. In this case, the principle applies: the less often this sign is detected, the higher the identification value.
- Relative independence. Identifying signs should be mutually independent of other properties that do not affect the identification process.
All signs, for a variety of reasons, have variability and variability. Such features are most clearly expressed in human handwriting. Individual symptoms may vary depending on living conditions. Taking into account all the circumstances affecting the state of the signs is of particular importance in formulating conclusions about the absence or presence of identity.