The forensic technical examination of documents is a study that is assigned to identify evidence, identify papers and their means of production. This task is achieved using special knowledge and methods of physics, chemistry, technology and equipment itself.
Objects of study
When a technical and forensic examination of documents is appointed, the following papers are checked:
- The materials by which they are made.
- Technical equipment for details.
- Documentation.
- Hardware for their decoration.
- Products that are used to change content.
- Other items checked by the method under consideration.
Tasks
A forensic examination is aimed at solving the following problems:
- Identification. In this case, the person who printed the text is recognized, the products and materials are checked, the applied technical means are installed and parts of the documents are reproduced.
- Classification. The object is checked for belonging to a specific group.
- Diagnostic It checks how and when the paper was made, whether changes were made to it, and the original text is determined.
With the invention of new manufacturing methods, fake methods are also growing. The technical and forensic examination of documents is also developing.
Form Survey
Forms are issued and protected paper sheets with the details entered by printing or other means.
There are requirements for government securities. And in business it is customary to draw them up accordingly. Forms are needed to understand the source - the organization. They are made in printing houses where each order is numbered and duplicated. Forms with the emblem are made only at printing companies that have received the appropriate work licenses.
Fakes are different, depending on the formation of a forger, skills and the availability of equipment. For example, the text may be drawn. Then deviations, uneven intervals between lines and letters are visible. If letterpress is performed, then there is a convex relief, a thickening of the layer, a font difference, and so on. Flat printing is accompanied by a deviation of the sizes of images from characters from the original form, insufficient clarity, intermittent strokes and so on.
When a forensic forensic examination is carried out, together with the documents being examined, they provide original samples with the same printed form and ordered in the same printing house, under the same number. They are compared in all respects, on the basis of which conclusions are drawn.
In accordance with applicable law, printing products have the following security features:
- unique number;
- watermark;
- special fibers;
- ultraviolet luminescence;
- special print;
- background grids of two colors;
- thread of protection;
- protection against color photocopying.
It is unprofitable to produce a counterfeit whose original document was produced at a printing company. Therefore, simulation methods are usually used. This means obtaining effects that, when considered, resemble those used on the form, but made with other technologies.
The study of signatures and impressions of seals
A print impression is an image on paper made by a mechanical cliché application in order to assure authenticity.
Traditionally prints are faked as follows:
- by drawing;
- reproduction of clichés cut from leather, rubber or linoleum;
- by typing typographic letters;
- by means of copying.
The paper is falsified by printing in other ways. Most often, technical and forensic examination of documents reveals the use of modern technologies, which are also used in the manufacture of originals. For identification provide from 10 to 20 prints.
Signatures are falsified by stroke or imprinting. Depending on the execution, you can see:
- strokes from carbon paper;
- unusual location on the line;
- differences in the color of strokes;
- impressions;
- interruptions and decreased coordination;
- blurry;
- smudges;
- clots and more.
Supplement, overprint and cleaning
Insertions in the form of additional letters or additional prints are the addition of letters, words, text, or some kind of characters. The main features in this case are:
- difference in handwriting in size, slope of letters, arrangement;
- placement on fields, edges, lines;
- ink difference.
The cleaning is done mechanically - removal or scraping. Signs in this case are:
- ruffled paper, smaller thickness, damage to the protective mesh, the disappearance of gloss;
- traces of strokes of the text that was originally.
Replacing sheets and photos
An independent forensic examination is able to distinguish the replacement of one sheet or several according to the following criteria:
- different sizes of sheets;
- staple marks;
- shade of paper.
Replacement of photographs is carried out by re-sticking with subsequent re-drawing of the print, re-sticking with its preservation, stickers of the emulsion layer, which was taken from the print of the original photograph. It is possible to detect a fake in the absence of an imprint, mismatch of its parts on the photo and letterhead, density difference or the presence of other signs.
Establishment of the initial content
Forensic forensics is able to restore crossed out, drenched and smeared records. The methods used in this case detect and amplify differences in materials with which interference was applied. To do this, apply:
- research photography, when the difference is visible, for example, in x-rays, in the field of currents or oblique rays;
- copying by wet or diffuse copying,
- color separation;
- other methods.
The issues of forensic examination may include the reproduction of faded and faded texts, which is carried out using physical, chemical and physicochemical methods that enhance the difference between the applied strokes and the surface, luminescent analysis, IR spectral region, and more.
Burned documents that are dried, charred and often torn can sometimes be restored.
Establishment of prescription
Experts may wonder about the time taken to complete the recordings. In this operation, absolute and relative prescription are distinguished. In the first, it is established when the document is drawn up, and in the second - the sequence of entries in it.
At the same time, an independent forensic examination determines the absolute prescription by identifying unchanging signs over time (content, document basics, etc.) and variable (the age of the pastes used from ballpoint pens, inkjet ink, etc.). As for relative prescription, it is known: in paperwork it is customary to first enter the text, then sign the document, and then seal it. If this order is violated, then we can talk about installation. Such issues are also resolved by the forensic examination. Moscow, as the capital, has the most relevant centers. But in other cities, if necessary, such examinations are carried out.