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 technique involving the superimposition of a facial photograph or video of a known individual with an unidentified skull.
The accidental discharge of a firearm upon closing of the action.
Slap fingerprints (slaps) are taken by simultaneously pressing the fingers of one hand(i.e., without the thumb) onto a scanner or fingerprint card. Slaps are also known as fourfinger simultaneous plain impressions (although if the person has more than four fingerson a hand, all of the fingers may be included in the slap image).
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.
The condensed residue of suspended vapors and liquid products of incomplete combustion.
See backdraft.
A discoloration resulting from deposits of the solid constituents in smoke.
Combustion without flame, usually with incandescence and smoke.
Scar, (needle) mark, and tattoo information.
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.
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.
A solvent without analyte(s) or internal standard(s) of interest
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.
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.
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).
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.