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.
The examination of a firearm concerning its mechanical condition and operation. It is usuallyperformed to determine if all safety features are operable and/or if the firearm is capable of firing acartridge.
Checking to confirm that the software performs tasks as expected.
air pockets in a hair shaft caused by fungal growth.
air pockets in a hair shaft caused by fungal growth.
a train of pyrotechnic composition (usually black powder), often covering, or covered with, inexpensive materials such as twine, thread, or twisted paper, as well as a waterproofing material.
Discussion—Sub-types of fuse include cannon/hobby/pyrotechnic fuse and safety fuse.
a device composed of a pyrotechnic mixture in a tube, usually equipped to be ignited by a mechanical initiation mechanism.
Discussion—The common red 'fusee', or road flare, normally contains strontium nitrate, potassium perchlorate, sulfur, and some organic binders. Other constituents can include sawdust, potassium nitrate, aluminum or magnesium.
a device with explosive or nonexplosive components designed to initiate a train of fire or detonation in ordnance by an action such as hydrostatic pressure, electrical energy, chemical, impact, mechanical, time, acceleration or deceleration, and piezoelectric action, or a combination of these.
Checking to confirm that invalid, unexpected or nonsensical inputs to a computer program or module yield an acceptable response (e.g., an error message or other indication of a problem).
in facial identification, a FR system's database, which typically contains all known-person biometric references (samples or templates, or both).
the portion of the colorspace that can be represented or reproduced by a device or process.
The physical state of a substance that has no shape or volume of its own and will expand to take the shape and volume of the container or enclosure it occupies.
in image and video analysis, a function typically used to reduce image noise and detail using a specific mathematical function known as the 'Gaussian Kernel' or 'bell-curve.'
A commercial product with gelatin applied to a pliable backing used to lift impressions.
A commercial product with gelatin applied to a pliable backing used to lift impressions.
A public repository of DNA sequences maintained by the National Center for Biotechnology Information, part of the U.S. National Institutes of Health.
Acronym for Geopolitical Entities, Names and Codes, which is the United StatesGovernment profile of the ISO 3166 standards. This reflects the United States (U.S.)Government requirement to use names of countries, dependencies, areas of specialsovereignty, and administrative subdivisions that have been approved by the U.S. Boardon Geographic Names (BGN), the authority established under Public Laws 80-242 toprovide for uniformity in geographic nomenclature and orthography throughout theFederal Government. GENC is available at https://nsgreg.nga.mil/genc/registers.jsp
An individual’s culturally mediated social expression along the feminine-masculine continuum.
The tendency to respond to a class of stimuli that share some common characteristics (e.g., the presence of some compound) and that may vary across some other dimension (e.g., a concentration gradient) rather than only to the one which was originally conditioned.
as used with textile fibers, a grouping having similar chemical compositions or specific chemical characteristics.
Discussion—A generic name applies to all members of a group and is not protected by trademark registration. Generic names for manufactured fibers include, for example, rayon, nylon, and polyester. Generic names used in the United States for manufactured fibers were established as part of the Textile Fiber Products Identification Act enacted by Congress in 1954.
A type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition.
The entire genetic constitution of an individual; also, the alleles present at one or morespecific loci.
A level of taxonomic classification that defines a group of related species.
The level of taxonomic classification that defines a group of related species.
The level of taxonomic classification that defines a group of related species.
Conditions that reflect how the buried body or evidence affects the surrounding environment.
The interval in the migration process from a tooth's initial appearance through the gingival soft tissue to the point of final eruption.
an inorganic product of fusion that has been cooled to a rigid condition without crystallization.
Luminous burning of solid material without a visible flame.
Good Laboratory Practice. The United States has rules for GLP in 21CFR58. TheOrganization for Economic Co-operation and Development (OECD) has stated principlesof GLP.
Greenwich Mean Time.
Global Positioning System.
an individual particle of smokeless powder.
thick tablets having nearly equal width, breadth and thickness.
A group of citizens empaneled to investigate potential criminal conduct and/or determine whether probable cause exists to charge someone with a crime.
parallel set of linear, regularly repeating grooves that, when illuminated, produces dispersion of light into its requisite wavelengths with maxima and minima of light intensity as a consequence of interference.
Discussion—These maxima and minima vary in position with wavelength. This allows radiation of any given wavelength to be isolated from a mixture of wavelengths (for example, white light) and allows the grating to be used as part of a monochromator. The dispersion or ability to resolve separate wavelengths is expressed as the number of lines (or steps) in the grating per millimetre.
an image encoded with a single channel or component.
operation that modifies a single channel or component of image data (for example, a single color).
Ranges from an untrained canine up to but not including a certified canine. (See novice dog.)
A type of systematic pattern used to ensure thorough coverage of a defined area.
Visual (macroscopic) assessment of skeletal and dental materials.
A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and earth or to some conducting body that serves in place of the earth.
A current that flows outside the normal circuit path, such as (1) through the equipment grounding conductor; (2) through conductive material in contact with lower potential (such as earth), other than the electrical system ground (metal water or plumbing pipes, etc.); or (3) through a combination of these ground return paths.
A document that is advisory or informative in nature and that contains only nonmandatory provisions. A guide may contain mandatory statements such as when a guide can be used, but the document as a whole is not suitable for adoption into law.
Recommended practice that allows some discretion or leeway in its interpretation, implementation, or use. A set of general principles used to provide direction and parameters for decision making.
a generic term used for propellant powders used in firearms.
residues formed during the discharge of a firearm.