Dactyloscopy

FOTO: FSC “Ivan Vučetić”

Dactyloscopy is one of the most reliable and widely used methods for establishing the identity of individuals based on the friction ridge patterns of fingers, palms, and soles. In modern practice, dactyloscopy is a universally recognized scientific method and discipline, serving the purposes of individual recognition, identification, and the provision of physical and legal evidence of identity.

The origins of dactyloscopy in Croatia date back to 1904, when a fingerprint examination was conducted for the first time in Zagreb on a suspect accused of counterfeiting Czech crowns. The individual, Ambroz Zlamal, was fingerprinted on 13 May 1904.
From 1906 onwards, dactyloscopy became a routine method, and the first fingerprint collection was established in Zagreb. This collection remains an integral and indispensable part of the “Ivan Vučetić” Forensic Science Centre.

In September 1924, during the investigation of a aggravated theft scene in Zagreb, a finger mark was discovered and collected for the first time as physical evidence for identification purposes. The first fingerprint identification expert in Croatia was Stjepan Kreč, who in 1926 completed formal training in monodactyloscopy in Vienna. Shortly thereafter, a perpetrator was identified for the first time in this territory using a finger mark, in connection with a burglary at a commercial store located at Radićeva 1 in Zagreb; the individual was a Romanian national, Geis Heime Lutski.
Since 1953, the primary task of dactyloscopy and identification at this Centre has been the detection of finger marks using state-of-the-art detection techniques and the identification of persons based on fingerprint evidence.

The Department of Dactyloscopy and Identification encompasses the following areas of work:
Detection of finger marks - tasks in the field of finger mark detection include: examining items recovered from crime scenes under forensic light to visualize visible finger marks; selecting appropriate dactyloscopic detection methods depending on the type of surface (porous or non-porous, adhesive surfaces, and colored - e.g., bloody - surfaces) requiring fingerprint examination; and performing the fingerprint search itself. All activities are aimed at locating finger marks, which are then preserved in accordance with professional standards (using appropriate photographic methods, fingerprint lifters, and official reports).

On non-porous (non-absorbent) surfaces, such as various metals (e.g., firearms and cold weapons), PVC materials, glass objects, aluminum foils, and lacquered wooden or ceramic surfaces, the Cyanoacrilate fuming method is applied to develop finger marks. To enhance the contrast of the detected marks relative to the surface, additional dactyloscopic methods are employed for developing and coloring finger marks (e.g., fingerprint powders and/or liquid dyes such as Basic Yellow, Ardrox, etc.).
For porous surfaces (absorbent) surfaces, such as various types of paper, untreated wood, assorted paper-based colored materials, banknotes, plasterboards, etc., the Finger mark detection on porous surfaces is typically used, employing solutions such as ninhydrin, DFO, 1,2-indandione (1,2-IND), or Termanin.

In forensic practice, various types of self-adhesive tapes are frequently encountered. Finger mark examinations on their adhesive sides are performed using Detection of finger marks on adhesive surfaces, with reagent selection based on contrast principles. Typical reagents include Sticky Side, Wet Powder, Gentian Violet, and similar compounds.

For violent crimes (e.g., homicide, sexual assault, robbery) surfaces are often contaminated with blood. Visulisation of fingermarks using Amido Black solution  method is applied to develop fingerprints on such blood-contaminated surfaces.
In addition to laboratory analysis, fingerprint experts attend crime scenes to detect finger marks and use them for the identification of perpetrators. They also provide testimony in court.

These experts additionally conduct professional training for authorized law enforcement personnel and investigators, covering standards of practice and proper conduct at crime scenes.

Dactyloscopic examination of finger marks involves the comparison of finger marks with the prints of known individuals and suspects/convicted persons, with the aim of identifying the perpetrator of a criminal offense based on fingerprint evidence.

Tasks related to the identification of finger marks include dactyloscopic examination (Dactyloscopic expertise), i.e., the analysis and assessment of the usability of finger marks, as well as the comparison of these marks with the fingerprint records of known individuals and suspects/convicted persons.

After dactyloscopic examinations using the prints of specific known/suspect individuals, unidentified finger marks are searched against the ABIS (Automated Biometric Identification System) database, which includes the fingerprints of suspects and convicted persons from the Finger Mark and Mugshot Database.

The result of the ABIS search for each examined finger mark is a list of the ten (10) most similar fingerprint or palm prints (in the case of finger marko f a palm) from the Fingerprint and Mugshot database. These candidate prints are subsequently evaluated and examined by the forensic expert.


Dactyloscopic expertise i.e., the identification of individuals based on fingerprints, entails determining the identity of persons and human remains using fingerprint evidence.
Dactyloscopic expertise involves comparing fingerprints from unknown individuals with those of known persons.

Common purposes for conducting fingerprint identification include: detecting individuals using fraudulent identification; comparing fingerprints from unidentified human remains; and establishing the identity of persons unable to provide identification information themselves.

Within the framework of dactyloscopic examination, verification and evaluation of submitted fingerprints are performed via the Fingerprint and Mugshot Database, as well as comparative analysis of right index fingerprints.

Moreover, fingerprint identification and verification are conducted using submitted fingerprint data through international operational police cooperation channels (Interpol, Europol, Sirena, and others).

Furthermore, based on international agreements, an automated exchange of fingerprint (dactyloscopic) data has been established with EU Member States as well as with the United States.

During the Homeland War, dactyloscopy and identification played a crucial role, providing professional expertise in the identification of victims. This was achieved through the comparative analysis of right index finger impressions from unknown human remains with the right index finger impressions of known individuals.

From 2010 to the present, the Department of Dactyloscopy and Identification has accredited six (6) methods: five (5) in the field of finger mark detection, and one (1) in the field of dactyloscopic examination.

ACCREDITED METHODS IN THE FIELD OF FINGER MARK DETECTION:

In addition to accredited methods for finger mark detection, other techniques are employed to develop finger marks or enhance the contrast of developed marks, including: Development of finger marks by metal particle deposition under vacuum, Optical examination of evidence using forensic devices with variable light wavelengths, Powdering of surfaces with different types of fingerprint powders based on contrast principles, Application of SPR (Small Particle Reagent) suspension or Basic Yellow reagent.

For all non-accredited methods used within the Department of Dactyloscopy and Identification, standard operating procedures (SOPs) are prescribed to regulate their implementation.

The accredited method in the field of dactyloscopic examination is the method referred to as Dactyloscopic Expertise.

Within the Department of Dactyloscopy and Identification the method of “Biometric Facial Identification” is also applied. This method is based on the morphological comparison of facial components and sub-components using the submitted questioned material (video material - where the warrant must explicitly specify the particular individual depicted in the recording, or specific photographs) and known reference material. The known reference material must always depict the individual’s facial features in the same manner as they are shown in the questioned material.

The “Biometric Facial Identification” method encompasses the review and evaluation of the suitability of both questioned and uncontested material for comparative analysis, followed by the determination of examination results expressed in terms of a level of support.

In addition to the methods previously mentioned, for the purpose of identifying human remains, the method of Fingerprint Ridge Regeneratio is also applied.

The Department of Dactyloscopy and Identification continuously works on the professional development of its personnel and the development of new methods, with the aim of improving the quality of examinations and the reliability of results.

As a full member of the ENFSI Fingerprint Working Group, fingerprint experts actively participate in annual meetings and professional symposia, where they successfully complete proficiency tests.

It is also important to note that the Department of Dactyloscopy and Identification is actively engaged in international police cooperation with members of INTERPOL and EUROPOL.