ASTM E3391-24

• Abstract:

  SIGNIFICANCE AND USE; 3.1 These terms have particular application to gunshot residue analysis. In addition, several sources of definitions were used in the development of this terminology (1-7).3; SCOPE; 1.1 This terminology standard is a compilation of terms and corresponding definitions that are used in gunshot residue analysis. Some legal or scientific terms that are generally understood or defined adequately in other readily available sources are included. ; 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. ; 1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

• Status: Published
• Publication Date: 14-Jan-2024
• Technical Committee: E30 - Forensic Sciences
• Drafting Committee: E30.01 - Criminalistics

Overview

ASTM E3391-24: Standard Terminology Relating to Gunshot Residue Analysis (GSR) is an international standard developed by ASTM International. This standard provides a comprehensive compilation of terms and definitions commonly used in the field of gunshot residue analysis. These definitions are essential for forensic scientists, law enforcement, and legal professionals to ensure clear and consistent communication regarding gunshot residue (GSR) and its analysis.

ASTM E3391-24 was developed following internationally recognized principles on standardization, including the World Trade Organization’s Technical Barriers to Trade (TBT) Committee guidelines. The document ensures all values are expressed in SI units, promoting international compatibility and clarity.

Key Topics

This terminology standard addresses several foundational concepts and definitions relevant to gunshot residue analysis, including:

• Gunshot Residue (GSR): Residues formed during the discharge of a firearm, typically a mixture from the primer, propellant powders, and other sources found on the hands, clothing, or nearby surfaces.
• Primer GSR (pGSR): Residue specifically resulting from the initiation compounds in primer mixtures.
• Organic GSR: Residues composed of organic compounds from the propellant or primer.
• Inorganic GSR: Metal-based residues originating from the primer, cartridge case, or bullet.
• Accelerating Voltage, Beam Current, and Other Instrumentation Terms: Definitions relating to scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDS) equipment used in GSR analysis.
• Primer Types (Berdan, Boxer, Sinoxid): Terminology describing various priming mechanisms and compounds in ammunition.
• Ammunition Components: Terms such as centerfire cartridge, rimfire cartridge, oxidizer, initiator, frictionator, and sensitizer, which are key in understanding residue formation.

By standardizing these terms, ASTM E3391-24 helps reduce confusion and ensures consistency across forensic laboratories and criminal justice proceedings.

Applications

ASTM E3391-24 is used in a variety of practical contexts:

• Forensic Laboratories: Ensures standardized terminology when analyzing and reporting GSR findings.
• Law Enforcement: Aids in the reliable interpretation and communication of gunshot residue evidence in investigations.
• Legal Proceedings: Promotes clearer testimony and documentation in court concerning GSR evidence by using precise, internationally recognized terms.
• Scientific Research and Publications: Facilitates the consistent use of technical language in academic studies and forensic science literature.
• Training and Education: Serves as a foundational reference for training forensic examiners and students in GSR analysis processes and reporting.

By applying these definitions, forensic professionals and other stakeholders can communicate GSR results more effectively, enhancing the reliability and credibility of forensic evidence.

Related Standards

Several ASTM and international standards complement or frequently reference ASTM E3391-24, including:

• ASTM E1588: Practice for Gunshot Residue Analysis by Scanning Electron Microscopy/Energy Dispersive X-Ray Spectrometry (SEM/EDS). This standard outlines the analytical procedures for GSR testing, often cited alongside terminology.
• ASTM E3309: Guide for Reporting of Forensic Primer Gunshot Residue (pGSR) Analysis by SEM/EDS. Provides best practices for reporting the results of GSR analyses, making use of the standardized terms in E3391-24.
• SWGGSR (Scientific Working Group for Gunshot Residue) Guides: Additional resources for GSR testing protocols and guidelines.
• AFTE Glossary: Further terminology on firearms, ammunition, and toolmark identification relevant to GSR work.

Summary

Adoption of ASTM E3391-24 ensures that professionals involved in gunshot residue analysis use uniform terminology, supporting accuracy, transparency, and international cooperation. Its content supports best practices in forensic science, promoting confidence in the results of GSR analyses across the criminal justice system.

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3391 − 24
Standard Terminology Relating to
Gunshot Residue Analysis (GSR)
This standard is issued under the fixed designation E3391; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope accelerating voltage, n—voltage/electrical potential applied to
the filament that accelerates the electrons emitted by the
1.1 This terminology standard is a compilation of terms and
electron gun/filament. Flegler (1)
corresponding definitions that are used in gunshot residue
analysis. Some legal or scientific terms that are generally
beam current, n—current that impinges on the specimen.
understood or defined adequately in other readily available
Flegler (1)
sources are included.
NOTE 1—Also referred to as probe current.
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
Berdan primer, n—primer/case system, designed by Col.
standard.
Hiram Berdan, having two or more flash holes consisting of
a cup, explosive mixture, and covering foil or paper; the
1.3 This international standard was developed in accor-
anvil is an integral part of the cartridge case head in the
dance with internationally recognized principles on standard-
bottom of the primer pocket. AFTE Glossary, 6th Ed. (2)
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
boxer primer, n—ignition component consisting of a cup,
mendations issued by the World Trade Organization Technical
explosive mixture, anvil, and covering foil or paper disk that
Barriers to Trade (TBT) Committee.
together form the completed primer ready for assembly into
the primer pocket of a cartridge case. AFTE Glossary, 6th
2. Referenced Documents
Ed. (2)
2.1 ASTM Standards:
E1588 Practice for Gunshot Residue Analysis by Scanning
candidate particles, n—particles classified by the instrument
Electron Microscopy/Energy Dispersive X-Ray Spectrom- software based on detection of appropriate (as specified in
etry
Practice E1588) constituent elements as potential pGSR.
E3309 Guide for Reporting of Forensic Primer Gunshot E3309
Residue (pGSR) Analysis by Scanning Electron
centerfire cartridge, n—any cartridge that has its primer
Microscopy/Energy Dispersive X-Ray Spectrometry
central to the axis in the head of the case. AFTE Glossary,
(SEM/EDS)
6th Ed. (2)
3. Significance and Use
condenser lens aperture, n—metal strip mounted on a holder
3.1 These terms have particular application to gunshot
that is inserted into the column under the condenser lenses:
residue analysis. In addition, several sources of definitions
the strip can have three selectable holes or one fixed hole that
were used in the development of this terminology (1-7).
the electron beam passes through the center and stray
electrons are then captured by the surrounding plate. Gold-
4. Terminology
stein (3)
4.1 Definitions:
condenser lens current, n—current in the condenser lens
changes the spot size or diameter of the electron beam.
This terminology is under the jurisdiction of ASTM Committee E30 on
Goldstein (3)
Forensic Sciences and is the direct responsibility of Subcommittee E30.01 on
Criminalistics.
frictionator, n—provides sharp corners against which the
Current edition approved Jan. 15, 2024. Published January 2024. DOI: 10.1520/
E3391-24.
particles of sensitizer and initiator are forced by the move-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ment of the primer cup or case rim under the firing pin blow.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Frost (4)
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
gunpowder, n—a generic term used for propellant powders
The boldface numbers in parentheses refer to a list of references at the end of
this standard. used in firearms. SWGGSR (5)
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