Insights from our Advisory Board: Prof. Francesco Donato "Document Forgery and Forensic Investigations"

Published on 25th October, 2023

Insights from our Advisory Board: Prof. Francesco Donato

Prof. Francesco Donato, esteemed member of Protective Intelligence Network Advisory Board, is graduated in Law and obtained a specialization in Forensic Criminalistics at the Italian National Police Academy in Rome.

National Police Colonel, and former director of the Regional Forensic Police Center in Tuscany, he currently works as a consultant in forensic sciences, in particular in the field of ballistics, fraudolent documents and graphic analysis.

He is included in the Register of Experts of the Court of Florence, Italy.

Former lecturer in several university courses, such as the Postgraduate School of Forensic Medicine of the University of Florence, the Degree Course in Investigation Sciences at both the University of L'Aquila, and the Faculty of Political Sciences of the University of Bologna, is currently a lecturer in the university Course in Law and Investigation at the Faculty of Law of the University of Siena.

In the following text an in-depth exploration of document forgery and forensic investigations is presented. Dr. Donato meticulously outlines the various facets of falsification and the comprehensive range of examinations and analyses required to uncover and validate the authenticity of documents, shedding light on the complex and critical field of forensic document examination.

"Document Forgery and Forensic Investigations"

Dear reader, I take great pleasure in serving as a member of the Advisory Board for the Protective Intelligence Network in Singapore.

On numerous occasions, I have had the opportunity of offering recommendations and sharing my professional insights concerning cases presented by the intelligence network associated with this organization.

Today, I will share details about my work and the deep-seated passion that has driven me for the past 35 years.

Insights from our Advisory Board: Prof. Francesco Donato

The deliberate alteration of truth, encapsulated in the concept of forgery, presents two distinct aspects: the first aspect pertains to falseness as the antithesis of authenticity when a document originates from an entity not authorized or legitimate to issue it; this type of forgery is referred to as counterfeiting and signifies the complete falsity of the document itself.

The second aspect concerns falseness in opposition to truthfulness, where a structurally genuine document contains modified or substituted data; this second type of falseness is referred to as alteration. Both counterfeiting and alteration constitute the two facets of the so-called "material forgery," which are subject to examination and laboratory investigations.

The forgery of paper documents usually occurs through zincographic and/or lithographic processes, offset printing, readily accessible and inexpensive methods, or simply by scanning an image, acquired using computerized systems, and subsequently processed and printed in color using specific systems connected to the same computer.

Detecting falseness is always possible because the accuracy of photographic reproduction or computerized image acquisition, the starting point for forgery, is always relative and is further reduced during the printing process, where alterations to the original graphic elements almost always occur, resulting in less defined details compared to genuine ones.

Insights from our Advisory Board: Prof. Francesco Donato

Investigating the falseness or alteration of a document requires meticulous examination of both the overall and specific graphical and chromatic elements it contains.

This examination should be conducted under direct, grazing light, and for transparency, both in natural light and with the assistance of appropriate optical instruments at low and medium magnifications, as well as a stereoscopic microscope, in order to highlight all printing details and characteristics, as well as the presence of any anomalies on the paper substrate (such as abrasions, thinning of fibers, halos, imitation watermarks, etc.).

Subsequently, laboratory instrumental examinations are performed, compared to a genuine reference standard, to identify elements of falseness not directly visible.

Insights from our Advisory Board: Prof. Francesco Donato

Forensic investigations include the following examinations:

Direct Examinations

These are simple investigations that can be conducted without specialized equipment:

Comparison examination: Two apparently identical images are compared, placed side by side, but differing in a certain number of small details. The basis for this examination is having an authentic sample document to use as a reference. Examination by transmitted light: The specimen to be examined is subjected to diffused lighting; this examination can reveal erasures made with mechanical means (such as erasers or scrapers) or search for the presence of watermarks in the paper substrate.

Examination with a Wood lamp: The examined specimen is exposed to UV luminescent radiation; in addition to highlighting the luminescence of the paper, this examination can reveal anomalies or alterations caused by chemical erasures (use of chemicals or solvents).

Optical-Instrumental Examinations

These examinations involve non-destructive methods conducted in the laboratory using specialized equipment:

Grazing light microscopy: This examination is carried out with a microscope and a point light source grazing the substrate under examination. It allows for the assessment of the authenticity of dry seals or stamps, typically affixed to documents, as well as the presence of mechanical erasures. Grazing light incidence creates chiaroscuro effects on the paper's surface, highlighting its three-dimensional properties. Dry seals and stamps create imprints with raised and depressed areas, which can be well-documented using this examination, especially when they are affixed to photographs or stamps, allowing verification of the exact continuity of the groove between the substrate and the photo or stamp. Similarly, erasures with abrasive means can be more definitively highlighted compared to examination by transmitted light, as the paper fibers are raised due to the abrasive action of erasure, forming a characteristic "fuzz" easily visible under grazing light.

Luminescence analysis: This encompasses methods that, following the excitation of the examined specimen by an appropriate energy source, result in the emission of electromagnetic radiation in the visible region, leading to a change in the material's color. Depending on the light sources used for excitation, distinctions can be made between ultraviolet fluorescence, infrared luminescence, laser luminescence, laser-induced infrared luminescence, diffuse reflectance spectroscopy, and Fourier transform infrared spectroscopy. These optical-instrumental methods are primarily used in the study of printing inks, overlapping additional strokes, toners from photocopiers, and laser prints.

Examination with an ESDA instrument: This allows the identification of any pre-existing writings that are visually imperceptible on the examined sample. The method is based on the principles of electromagnetism. The specimen under investigation is covered with an ultra-thin transparent plastic film, onto which micro-particles of carbon are subsequently deposited. When subjected to high-voltage electric generator action (approximately 8,000 volts), these particles expand across the entire surface, making any "blind" grooves created by a previous writing visible.

Analytical Examinations

These examinations encompass all analysis systems aimed at studying the structure of both organic and inorganic matter. Concerning documents, paper material and printing inks are examined from a mercantile perspective to ascertain the intimate constitution of the components, which are precisely identified and can also be typified.

These analytical examinations, which entail partial destruction of the specimen, even in micro-quantities, fall under the category of non-repeatable investigations that must be authorized in advance by the Judicial Authority.

Among these examinations are chromatographic analyses (thin-layer chromatography TLC, gas chromatography and mass spectrometry, high-pressure liquid chromatography HPLC), IR and UV spectrophotometry, and SEM-EDX analysis with scanning electron microscopy.


Concluding, it is evident that if one wishes to obtain certain and secure answers in the face of a suspected case of document forgery, the relevant examination must necessarily pass through a forensic laboratory.

The future prospects in this important field of investigation are, however, closely tied to the scientific evolution of research and the professional training of those involved in the field.

Dr. Francesco Donato

Forensic Criminalist - Partner, International Society of Criminology