Forensic Ballistics and Toolmark Analysis
The use of firearms is mostly related to serious crimes such as war crimes, murders, robberies and similar criminal activities and offences. Examination of firearms trace evidence, whether they are gunshot residues or mechanical traces on fired cartridge cases and bullets, leads to the elucidation of the most serious crimes.
The traditional theory of the identification for the purpose of forensic firearms and toolmarks examination is based on creation of mechanical traces of tools. From the viewpoint of the judicial value of evidence and criminal investigation, the result of such examination represents decisive evidence in linking the crime scene to the means of execution (firearms or tools).
As a modern scientific discipline, the theory of the identification of firearm and tool traces for the purpose of forensic firearms and toolmarks examination began at the beginning of the twentieth century with the appearance of the first microphotographs, and in the late 1920s with the appearance of the first comparative microscope.
American Association of Firearm and Toolmark Examiners (AFTE) played a major role in the recognition of scientific contribution from the field of firearms and toolmarks examination; their conclusions together with their well-defined terminology and trace-evidence identification theory have been accepted in the world, including in Croatia.
The Centre become a full member of the European Network of Forensic Science Institutes (ENFSI) in 1998, with its forensic experts working in the fields of forensic firearms and ballistics as well as toolmarks examination. These experts become full and active members of the working groups for firearms and gunshot residues (EWG Firearms/GSR) and shoeprint and toolmarks (EWG Marks).
The current ballistic laboratory is equipped with cutting-edge systems, instruments and equipment, such as ballistic identification system “IBIS BrassTrax, BulletTrax and MatchPoint“ with digital databases of fired cartridge cases/shells and bullets, modern comparative microscopes „Leica FSC“ and „Projectina VisionX“, scanning electron microscope with energy dispersive x-ray detector, laser engraver, ballistic recovery tank and mobile base for remotely firing a weapon with a device for measuring the speed of the bullet, which are used in the most exacting ballistic examination. The Centre also houses the Collection of Firearms, containing over 1500 pieces of different firearms that are used for educational purposes, for the identification of firearms and test firing.
In the field of forensic firearms and ballistics, the following examinations are preformed:
Toolmarks
The Laboratory for Mechanoscopic Examinations is equipped with state-of-the-art instruments and devices, including a footwear outsole impression processing scanner (GLSCAN), a digital video microscope (Ash, Inspex HD 1080p VESA), as well as an advanced system for the identification of footwear and vehicle tire impressions, and the ToolScan digital recorder for mechanical traces. These systems enable the storage of questioned impressions (a repository of questioned traces), their mutual comparison, as well as comparison with test impressions obtained from seized footwear, tires, or tools, for identifying the specific footwear, tire, or tool from which the questioned impression originated. The system’s continuously updated database currently contains approximately 22,000 test footwear outsole impressions from most major global manufacturers. The laboratory also uses a Regula magneto-optical device for conducting non-destructive restoration of markings on metals.
In the field of mechanoscopic examinations, the following types of analyses are conducted:
List of accredited methods in the areas of ballistics and marks:
The traditional theory of the identification for the purpose of forensic firearms and toolmarks examination is based on creation of mechanical traces of tools. From the viewpoint of the judicial value of evidence and criminal investigation, the result of such examination represents decisive evidence in linking the crime scene to the means of execution (firearms or tools).
As a modern scientific discipline, the theory of the identification of firearm and tool traces for the purpose of forensic firearms and toolmarks examination began at the beginning of the twentieth century with the appearance of the first microphotographs, and in the late 1920s with the appearance of the first comparative microscope.
American Association of Firearm and Toolmark Examiners (AFTE) played a major role in the recognition of scientific contribution from the field of firearms and toolmarks examination; their conclusions together with their well-defined terminology and trace-evidence identification theory have been accepted in the world, including in Croatia.
The Centre become a full member of the European Network of Forensic Science Institutes (ENFSI) in 1998, with its forensic experts working in the fields of forensic firearms and ballistics as well as toolmarks examination. These experts become full and active members of the working groups for firearms and gunshot residues (EWG Firearms/GSR) and shoeprint and toolmarks (EWG Marks).
The current ballistic laboratory is equipped with cutting-edge systems, instruments and equipment, such as ballistic identification system “IBIS BrassTrax, BulletTrax and MatchPoint“ with digital databases of fired cartridge cases/shells and bullets, modern comparative microscopes „Leica FSC“ and „Projectina VisionX“, scanning electron microscope with energy dispersive x-ray detector, laser engraver, ballistic recovery tank and mobile base for remotely firing a weapon with a device for measuring the speed of the bullet, which are used in the most exacting ballistic examination. The Centre also houses the Collection of Firearms, containing over 1500 pieces of different firearms that are used for educational purposes, for the identification of firearms and test firing.
In the field of forensic firearms and ballistics, the following examinations are preformed:
- Examination of weapons;
- Examination of ammunition;
- Comparative testing of cartridge cases/shotshells and bullets (to determine the weapon from which the questioned ballistic evidence was fired; crosscheck of ballistic evidence through open case files; determination of the type of firearm used);
- Gunshot residue analysis (detection of entrance/exit bullet hole, shooting angle, and SEM/EDX Gunshot Residue Analysis);
- Shooting distance estimation;
- Shooting incident reconstruction
- Disabled weapon inspection.
Toolmarks
The Laboratory for Mechanoscopic Examinations is equipped with state-of-the-art instruments and devices, including a footwear outsole impression processing scanner (GLSCAN), a digital video microscope (Ash, Inspex HD 1080p VESA), as well as an advanced system for the identification of footwear and vehicle tire impressions, and the ToolScan digital recorder for mechanical traces. These systems enable the storage of questioned impressions (a repository of questioned traces), their mutual comparison, as well as comparison with test impressions obtained from seized footwear, tires, or tools, for identifying the specific footwear, tire, or tool from which the questioned impression originated. The system’s continuously updated database currently contains approximately 22,000 test footwear outsole impressions from most major global manufacturers. The laboratory also uses a Regula magneto-optical device for conducting non-destructive restoration of markings on metals.
In the field of mechanoscopic examinations, the following types of analyses are conducted:
- • Examination of toolmarks;
- • Shoeprint examination;
- • Mechanical fitting (physical matching) of sample fragments;
- • Restoration of markings on metal surfaces (determination of serial numbers and identifying marks);
- • Evidence identity determination of evidence.
List of accredited methods in the areas of ballistics and marks:
- Comparative bullets testing;
- Comparative cartridge cases/shotshells testing;
- SEM/EDX Gunshot Residue examination;
- Detection of traces of gunpowder using Walker test;
- Detection of traces of copper using DTO-test;
- Detection of traces of lead using Na-Rhodizonat test;
- Shoeprint examination;
- Toolmarks examination.