Core activities
Experts within the GSR examination field of expertise deal with particles formed through the rapid cooling of the discharge gases and solid matter. These particles originate both from partially reacted components of the primer and propellant, and from the metallic components of the ammunition and firearm.
Activities that fall within the GSR examination field of expertise are:
- analysis of samples e.g. from the hands of suspects, weapons, clothing, furniture and other items for the presence of GSR particles and the differentiation between GSR particles and any environmental particles like fireworks, brake pads, etc.;
- GSR comparison studies in order to obtain more information on the origin of the GSR particles;
- assisting with and advising on crime scene examination and crime scene processing, in particular selection of items and sampling;
- determination of shooting distance by examining pieces of evidence such as clothing of victims;
- determining damage and shooting direction in order to establish the relative positions of the victim (or object) and shooter;
- performing scientific testing with experimental setups to examine shooting incident hypotheses.
Boundaries of the field of expertise
Some activities of the GSR examination field of expertise show an overlap to a certain extent with other fields of expertise, but for all fields specific knowledge and experience are needed that set experts within these fields apart from each other. The expert in GSR examination is aware of the possibilities and restrictions of his fields of expertise in relation to other fields of expertise, as mentioned below.
The expert in GSR Examination can assist and advise the police on site in these activities.
Forensic Weapon and Ammunition Examination
The Forensic Weapon and Ammunition field of expertise is concerned with:
- comparative bullet and cartridge case examination;
- weapon-technical examination for the purpose of reconstruction;
- forensic ballistics examination (exterior ballistics).
Forensic Pathology
The tasks of a forensic pathologist are:
- to establish the cause and mechanism of death (including trigger and pre-existing pathology);
- to establish or to help establish the identity of the deceased;
- to establish or to help establish the nature, cause and consequences of any injuries;
- to establish or to help establish the manner of death.
Explosions and Explosives Examination
Explosions and explosives incidents differ from shooting incidents. The Explosions and Explosives field of expertise primarily deals with the following examinations:
- examination of intact factory produced and improvised explosive constructions;
- identification of intact presumably explosive substances and possible raw materials for explosives;
- research of explosions.
Experts in the field of Gunshot Residue have a shared knowledge of the process of production and distribution of materials that are produced when a firearm is discharged.
The following subfields of Gun Shot Residue field of expertise are distinguished in the register:
- 010.1 Gunshot Residue Examination - Instrumental Analysis and Interpretation
- 010.2 Gunshot Residue Examination - Shooting distance and directions
When submitting a request for registration, the expert must stipulate which specific subfield(s) are being applied for and they will be assessed accordingly by the NRGD.
010.1 Gunshot Residue - Instrumental Analysis and Interpretation
The expert in the subfield of Instrumental Analysis and Interpretation is concerned with the following activities:
- Identifying the presence and distribution of GSR particles on samples, by instrumental analysis;
- Comparison of GSR particles to reference samples from spent cartridges in order to obtain more information on the origin of the GSR particles;
- Examination of particle residue produced by ammunition;
- Interpreting the analytical results in the context of the case.
010.2 Gunshot Residue – Shooting distance and directions
The expert in the subfield of Shooting distance and direction has demonstrable knowledge of the work executed by the expert in GSR - Instrumental Analysis. Furthermore, a GSR expert Shooting distance and direction is concerned with the following activities:
- Determination of shooting distance by examining pieces of evidence such as clothing of victims;
- Determining damage and shooting direction in order to establish the relative positions of the victim (or object) and shooter;
- Performing scientific testing with experimental setups to examine shooting incident hypotheses.