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.
A protective device to permit dry firing without damage to the firing pin.
Extraction of an audio signal from an original recording in a way that disrupts thecontinuity and time record of the original recording.
Aerosol waxes used to coat the surface of snow impressions prior to casting.
An accelerated plaster that is applied in a prescribed way and is capable of casting all forms of snowimpressions.
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.
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.
The legal entity or vendor company which created and/or provides a software program.
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.
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).
A set of instructions, modules or procedures, that allow for a certain type of computer operation. Interchangeable terms include software application and software product.
Individual trial designed to evaluate specific software functions.
Different categories of trials that comprise the software internal validation.
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.
a device used to collect virtually undisturbed sub-surface soil samples for documenting a soil profile.
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.
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.
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.
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.
in TLC, a mixture of components to be separated.
A solvent without analyte(s) or internal standard(s) of interest
the transfer of chemical compounds from a material to a solvent.
the final point reached by the mobile phase as it flows up or across the TLC plate during development of the chromatogram.
an area of the body, such as head, pubic, or leg; synonymous with "body area".
Black particles of carbon produced in a flame.
(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.
list of instructions written in a programming language used to construct a computer program.
An opinion of same source, an opinion of different sources, or an inconclusive opinion
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.
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.
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.
Chipping or pitting of concrete or masonry surfaces.
A moving particle of solid material that emits radiant energy due either to its temperature or the process of combustion on its surface.
The locations of defects (or damage/breakage) in relation to each other throughout the skeleton.
A vocalizing human, whether or not the vocalizations contain speech. An interlocutormight be a synthesized voice, which can be considered a speaker within the contextof this standard.
The fundamental unit of taxonomic classification. There is no singular species definition in biology. Essentially the term denotes a group of organisms with a unique shared evolutionary lineage.
The fundamental unit of taxonomic classification. There is no singular species definition in biology. Essentially the term denotes a group of organisms with a unique shared evolutionary lineage.
The fundamental unit of taxonomic classification. There is no singular species definition in biology. Essentially the term denotes a group of organisms with a unique shared evolutionary lineage.
The fundamental unit of taxonomic classification. There is no singular species definition in biology. Essentially the term denotes a group of organisms with a unique shared evolutionary lineage.
Level of taxonomic classification between subspecies and genus.
A reference to studies generally performed during developmental validation of forensic testing assays to assess if non-targeted species are detected in an assay (e.g., detection of microbial DNA in a human assay). The detection of non-targeted species does not necessarily invalidate the use of the assay, but may help define the limitations of the assay.
A reference to studies generally performed during developmental validation of forensic testing assays to assess if non-targeted species are detected in an assay (e.g., detection of microbial DNA in a human assay). The detection of non-targeted species does not necessarily invalidate the use of the assay, but may help define the limitations of the assay.
The ratio of the average molecular weight of a gas or vapor to the average molecular weight of air, or the ratio of the density of a gas to the density of dry air at standard temperature and pressure.
The ratio of the mass of a given volume of a substance to the mass of an equal volume of water at a temperature of 4C.
Ability of a method to distinguish between the targeted analyte and other non-targeted substances.
Measures the proportion of actual negatives that are correctly identified as such.