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The Organization of Scientific Area Committees for Forensic Science

OSAC Lexicon

The OSAC Lexicon is a compendium of forensic science terms and definitions. This terminology tool was created to help bring consistency and understanding to the way terms are used by the various forensic science. Use of the OSAC Lexicon does not replace the need to reference the original published source.

The terms and definitions in the OSAC Lexicon come from the published literature, including documentary standards and technical reports. It is continually updated with the latest work from OSAC units, as well as terms from newly published documentary standards and standards elevated to the OSAC Registry.

Gradually terms are evaluated and harmonized by the OSAC to a single term. This process results in an OSAC Preferred Term. An OSAC Preferred Term is a term, along with its definition, that has undergone review and evaluation by the FSSB Terminology Task Group and has been approved by the FSSB. The FSSB recommends that subcommittees use OSAC Preferred Terms when drafting standards.

The OSAC Lexicon should be the primary resource for terminology and used when drafting and editing forensic science standards and other OSAC work products. 

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Smear
a transfer of paint resulting from contact between two objects; these transfers can consist of co-mingled particles from two or more sources, fragments, or contributions from a single source.
Committee
Trace Materials
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Smoke

The airborne solid and liquid particulates and gases evolved when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass.

Committee
Fire & Explosion Investigation
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
NFPA 921:2021 Guide for Fire and Explosion Investigations. The National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA, 2021. Source link
Term link
Smoke Condensate

The condensed residue of suspended vapors and liquid products of incomplete combustion.

Committee
Fire & Explosion Investigation
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
NFPA 921:2021 Guide for Fire and Explosion Investigations. The National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA, 2021. Source link
Term link
Smoke Explosion

See backdraft.

Committee
Fire & Explosion Investigation
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
NFPA 921:2021 Guide for Fire and Explosion Investigations. The National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA, 2021. Source link
Term link
Smoke Staining

A discoloration resulting from deposits of the solid constituents in smoke.

Committee
Fire & Explosion Investigation
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
NFPA 921:2017 Guide for Fire and Explosion Investigations. The National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA, 2017. Source link
Term link
Smokeless Powder
an explosive designed to deflagrate with minimal smoke production and used in ammunition as a propellant; can be single, double, or triple base. Discussion—Some smokeless powders can detonate with proper initiation.
Committee
Ignitable Liquids, Explosives & Gunshot Residue
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Smokeless Powder
a propellant and low explosive composed of nitrocellulose and other organic and inorganic compounds
Committee
Interdisciplinary
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Smoldering

Combustion without flame, usually with incandescence and smoke.

Committee
Fire & Explosion Investigation
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
NFPA 921:2021 Guide for Fire and Explosion Investigations. The National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA, 2021. Source link
Term link
Smt

Scar, (needle) mark, and tattoo information.

Committee
Interdisciplinary
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/NIST-ITL 1-2011 Update:2015 Data Format for the Interchange of Fingerprint, Facial & Other Biometric Information. ANSI/National Institute of Standards and Technology, 2011. Source link
Term link
smudge

A handwritten or machine printed character smeared or streaked, unintentionally, onto an adjacent area.

Committee
Forensic Document Examination
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ASB Technical Report 071 Forensic Document Examination: Terms and Definitions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2025. Source link
Term link
Snap Cap

A protective device to permit dry firing without damage to the firing pin.

Committee
Firearms & Toolmarks
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB 093 Standard Test Method for the Forensic Examination and Testing of Firearms. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2020. Source link
Term link
Snip (V)

Extraction of an audio signal from an original recording in a way that disrupts thecontinuity and time record of the original recording.

Committee
Interdisciplinary
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/NIST-ITL 1-2011 Update:2015 Data Format for the Interchange of Fingerprint, Facial & Other Biometric Information. ANSI/National Institute of Standards and Technology, 2011. Source link
Term link
Snow Print Powder
An accelerated plaster that is applied in a prescribed way and is capable of casting all forms of snow impressions.
Committee
Footwear & Tire
Date Added to Lexicon
Technical Report/Other Source (Author, Title of report. Publisher, Year.)
ASB TR 097, Terminology Used for Forensic Footwear and Tire Evidence. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2019. Source link
Term link
Snow Print Wax, Snow Impression Wax
Aerosol waxes used to coat the surface of snow impressions prior to casting.
Committee
Footwear & Tire
Date Added to Lexicon
Technical Report/Other Source (Author, Title of report. Publisher, Year.)
ASB TR 097, Terminology Used for Forensic Footwear and Tire Evidence. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2019. Source link
Term link
Social Maturity

The period of behavioral maturation that appears to be correlated, in species in which it has been studied, with changes in brain chemistry. Canines' temperaments can be considered relatively stable after this period, although learning continues. The broad range cited for social maturity is 12 to 36 months, and the narrow range cited is 18 to 24 months.

Committee
Dogs & Sensors
Date Added to Lexicon
Technical Report/Other Source (Author, Title of report. Publisher, Year.)
ANSI/Academy Standards Board (ASB), Crime Scene/Death Investigation - Dogs and Sensors - Terms and Definitions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2017. Source link
Term link
Socialization

The exposure of canines to other canines, humans, and animals of different species during the sensitive period when they are best able to begin to learn about such stimuli.

Committee
Dogs & Sensors
Date Added to Lexicon
Technical Report/Other Source (Author, Title of report. Publisher, Year.)
ANSI/Academy Standards Board (ASB), Crime Scene/Death Investigation - Dogs and Sensors - Terms and Definitions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2017. Source link
Term link
Software Developer

The legal entity or vendor company which created and/or provides a software program.

Committee
Human Forensic Biology
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB Best Practice Recommendation 114 Best Practice Recommendations for Internal Validation of Software used in Forensic DNA Laboratories. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2022. Source link
Term link
Software Internal Validation

Confirmation, through the provision of objective evidence, derived from a series of documented tests, of the compliance of a software system with intended use and applicable guidelines.

Committee
Human Forensic Biology
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB Best Practice Recommendation 114 Best Practice Recommendations for Internal Validation of Software used in Forensic DNA Laboratories. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2022. Source link
Term link
Software Module

Part of a software program. Programs are typically composed of one or more independently developed modules. Modules may be acquired as additions to a software program already in use, or they may be fully integrated into the software program (e.g., add-ins/plug-ins, and macros).

Committee
Human Forensic Biology
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB Best Practice Recommendation 114 Best Practice Recommendations for Internal Validation of Software used in Forensic DNA Laboratories. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2022. Source link
Term link
Software Program

A set of instructions, modules or procedures, that allow for a certain type of computer operation. Interchangeable terms include software application and software product.

Committee
Human Forensic Biology
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB Best Practice Recommendation 114 Best Practice Recommendations for Internal Validation of Software used in Forensic DNA Laboratories. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2022. Source link
Term link
Software Test

Individual trial designed to evaluate specific software functions.

Committee
Human Forensic Biology
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB Best Practice Recommendation 114 Best Practice Recommendations for Internal Validation of Software used in Forensic DNA Laboratories. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2022. Source link
Term link
Software Test Types

Different categories of trials that comprise the software internal validation.

Committee
Human Forensic Biology
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB Best Practice Recommendation 114 Best Practice Recommendations for Internal Validation of Software used in Forensic DNA Laboratories. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2022. Source link
Term link
Soil
sediments or other unconsolidated accumulations of solid particles (for example, minerals and organic matter) that are produced by the physical, chemical, and biological disintegration of parent material, or which has the ability to support rooted plants in a natural environment, or both; and which can include manufactured materials. Discussion—Within this document, "soil" includes native soil, as well as unconsolidated material emplaced by human activities.
Committee
Trace Materials
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Soil Core Sampler [Soil Corer; Soil Probe]
a device used to collect virtually undisturbed sub-surface soil samples for documenting a soil profile.
Committee
Trace Materials
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Soil Horizon
a layer of soil or soil material approximately parallel to the land surface and differing from adjacent genetically related layers in physical, chemical, and biological properties or characteristics such as color, structure, texture, consistency, kinds and numbers of organisms present, degree of acidity or alkalinity, etc.
Committee
Trace Materials
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Soil Profile
a vertical section of soil exposed from the ground surface to a depth of interest. A soil profile can be observed in a freshly dug pit, along a road bank, or in many other places.
Committee
Trace Materials
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Solid-Phase Based Purification

A method of isolating DNA from cells involving selective absorption to small silica or other particles/membranes, removal of non-DNA materials by washing, and release of DNA from the particles/membranes for analysis.

Committee
Human Forensic Biology
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB 023 Standard for Training in Forensic DNA Isolation and Purification Methods. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2020. Source link
Term link
Solid-Phase Microextraction, SPME
an extraction technique where the analytes from a sample are adsorbed onto a fiber coated with an adsorptive medium and thermally desorbed into the injection port of a gas chromatograph.
Committee
Ignitable Liquids, Explosives & Gunshot Residue
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Solute
in TLC, a mixture of components to be separated.
Committee
Trace Materials
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Solvent Extraction
the transfer of chemical compounds from a material to a solvent.
Committee
Ignitable Liquids, Explosives & Gunshot Residue
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Solvent front
the final point reached by the mobile phase as it flows up or across the TLC plate during development of the chromatogram.
Committee
Trace Materials
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Somatic Region
an area of the body, such as head, pubic, or leg; synonymous with "body area".
Committee
Trace Materials
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Soot

Black particles of carbon produced in a flame.

Committee
Fire & Explosion Investigation
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
NFPA 921:2021 Guide for Fire and Explosion Investigations. The National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA, 2021. Source link
Term link
Source

(1) The point of origin of the odor/scent. (2) The skill is for the canine to locate the source by arriving at its threshold for that odor/scent, then uses different thresholds to reach a point where the odor/scent is located. When a canine reaches the source, it should make a final response as it has been conditioned to make.

Committee
Dogs & Sensors
Date Added to Lexicon
Technical Report/Other Source (Author, Title of report. Publisher, Year.)
ANSI/Academy Standards Board (ASB), Crime Scene/Death Investigation - Dogs and Sensors - Terms and Definitions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO 80904, 2017. Source link
Term link
source

An area of friction ridge skin of an individual from which an impression originated.

Committee
Friction Ridge
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ASB Standard 013 Standard for Friction Ridge Examination Conclusions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2025. Source link
Term link
source

An area of friction ridge skin of an individual from which an impression originated. The Fingerprint Sourcebookb

Committee
Friction Ridge
Date Added to Lexicon
Technical Report/Other Source (Author, Title of report. Publisher, Year.)
ASB Technical Report 012, Technical Report on the Articulation of the Reasoning and Foundational Principles Behind Friction Ridge Examinations. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2025. Source link
Term link
source (of optical radiation)

Object that produces light or other radiant flux. (CIE S 017/E:2011 ILV)

Committee
Forensic Document Examination
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ASB Technical Report 071 Forensic Document Examination: Terms and Definitions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2025. Source link
Term link
Source Code
list of instructions written in a programming language used to construct a computer program.
Committee
Facial & Iris Identification
Digital Evidence
Video/Imaging Technology & Analysis
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
source conclusion (synonym of conclusion)

Opinion stated by an examiner after interpretation of observed data. The opinion is the professional judgment that the observed data can offer support for one proposition over another.

Committee
Friction Ridge
Date Added to Lexicon
Technical Report/Other Source (Author, Title of report. Publisher, Year.)
ASB Technical Report 012, Technical Report on the Articulation of the Reasoning and Foundational Principles Behind Friction Ridge Examinations. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2025. Source link
Term link
source conclusions

An opinion of same source, an opinion of different sources, or an inconclusive opinion

Committee
Firearms & Toolmarks
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB 102 Standard for Verification of Source Conclusions in Toolmark Examinations . AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2025. Source link
Term link
source exclusion

The conclusion that two friction ridge impressions did not originate from the same source.

Committee
Friction Ridge
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ASB Standard 013 Standard for Friction Ridge Examination Conclusions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2025. Source link
Term link
source exclusion (EXC)

The conclusion that the observed data provide substantially stronger support for the proposition that the questioned impression originated from a different source than the exemplar impressions compared.

Committee
Friction Ridge
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB Best Practice Recommendation 166 Best Practice Recommendation for Comparison and Evaluation of Friction Ridge Impressions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2024. Source link
Term link
source identification

The conclusion that the observed data provides substantially stronger support for the proposition that the two impressions originated from the same source rather than different sources.

Committee
Friction Ridge
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ASB Standard 013 Standard for Friction Ridge Examination Conclusions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2025. Source link
Term link
source identification (ID)

The conclusion that the observed data provide substantially stronger support for the proposition that the two impressions originated from the same source rather than different sources.

Committee
Friction Ridge
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASB Best Practice Recommendation 166 Best Practice Recommendation for Comparison and Evaluation of Friction Ridge Impressions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2024. Source link
Term link
source level

in comparative examinations, the evaluation of whether the items originated from the same or different sources. 

Discussion—Consideration is given to how discriminating and rare the characteristics of the evidence are (for example, glass fragments originated from antique glass versus the glass fragments originated from modern glass; the paint originated from a single layer of white paint versus the paint originated from a multi-layered, multi-colored paint).
 

Committee
Trace Materials
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428, 2025. Source link
Reprinted, with permission, from ASTM E1732 Standard Terminology Relating to Forensic Science, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard is available from ASTM International, https://www.astm.org
Term link
Source Representation

The image, recording, or other signal from which a biometric type record (see derivedrepresentation) is derived. A source representation may be included as a Type-20 recordin a transaction.

Committee
Interdisciplinary
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ANSI/NIST-ITL 1-2011 Update:2015 Data Format for the Interchange of Fingerprint, Facial & Other Biometric Information. ANSI/National Institute of Standards and Technology, 2011. Source link
Term link
spacing

The distance between characters, words, or lines.

Committee
Forensic Document Examination
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
ASB Technical Report 071 Forensic Document Examination: Terms and Definitions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2025. Source link
Term link
Spalling

Chipping or pitting of concrete or masonry surfaces.

Committee
Fire & Explosion Investigation
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
NFPA 921:2021 Guide for Fire and Explosion Investigations. The National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA, 2021. Source link
Term link
Spark

A moving particle of solid material that emits radiant energy due either to its temperature or the process of combustion on its surface.

Committee
Fire & Explosion Investigation
Date Added to Lexicon
Standard Source (Designation Number Title of Standard. Publisher, Place, Year.)
NFPA 921:2021 Guide for Fire and Explosion Investigations. The National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA, 2021. Source link
Term link
spatial distribution

The locations of defects (or damage/breakage) in relation to each other throughout the skeleton.

Committee
Forensic Anthropology
Date Added to Lexicon
Technical Report/Other Source (Author, Title of report. Publisher, Year.)
ASB Technical Report 214, Forensic Anthropology: Terms and Definitions. AAFS Academy Standards Board (ASB), 410 North 21st Street, Colorado Springs, CO, 2026. Source link
Term link
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