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 means and methods for characterizing fractured specimens or compounds.
High-speed missiles that are the result of an explosion and may be part of the explosive casing; container; earth; building material; target area; or other items affected by the explosion.
In video analysis, the lines of spatial information of a video signal
In video analysis, the lines of spatial information of a video signal. DISCUSSIONFor interlaced video, a frame consists of two fields, one of odd lines and one of even lines, displayed in sequence. For progressive scan (non-interlaced) video, the frame is written through successive lines that start at the top left of the picture and finish at the bottom right.
The internal bony structures that give the shape and proportion to the canine.
The internal bony structures that give the shape and proportion to the canine.
The plane determined by the lowest point of the left eye socket and the tragions of theears.
See unallocated space
See unallocated space
A seasonal surface sediment layer 1 to 5 cm thick occurring on bare ground that has been disaggregated or puddled by radiant heating and cooling to produce freeze/thaw cycles while very moist or wet.
The rate at which an event occurs.
A human scent pathway that has been present for a short period of time. A trail that is under 24 hours old.
provides sharp corners against which the particles of sensitizer and initiator are forced by the movement of the primer cup or case rim under the firing pin blow. Frost
The examination of impressions from fingers, palms or soles, for identification purposes.
An image of an impression from the palmar surfaces of the hands or fingers, or from theplantar (sole) surfaces of the feet or toes.
The volar skin surface of the surfaces of the hands and fingers, and the plantar surfaces ofthe feet and toes.
In facial identification, a facial image captured from directly in front of the subject with the focal plane approximately parallel to the plane of the subjects face
In facial identification, a facial image cap- tured from directly in front of the subject with the focal plane approximately parallel to the plane of the subject's face.
Any substance capable of reacting with oxygen and oxygen carriers (oxidizers) with the evolution of heat.
A material that will maintain combustion under specified environmental conditions.
a material that will maintain combustion under specified environmental conditions.
a material that will maintain combustion under speci- fied environmental conditions. NFPA 921, 3.3.95
chemical compound or mixture of compounds added to a fuel for various purposes.
chemical compound or mixture of com- pounds added to a fuel for various purposes.
Natural gas, manufactured gas, LP-Gas, and similar gases commonly used for commercial or residential purposes such as heating, cooling, or cooking.
Natural gas, manufactured gas, LP-Gas, and similar gases commonly used for commercial or residential purposes such as heating, cooling, or cooking.
The total quantity of combustible contents of a building, space, or fire area, including interior finish and trim, expressed in heat units or the equivalent weight in wood.
indicating a ratio of oxygen-to-fuel that provides less oxygen than needed for optimum combustion of the fuel.
A fire in which the heat release rate and growth rate are controlled by the characteristics of the fuel, such as quantity and geometry, and in which adequate air for combustion is available.
Indicating a ratio of oxygen-to-fuel that provides less oxygen than needed for optimum combustion of the fuel.
A full finger view is a rolled or plain image of a full-length finger showing all segments.An entire joint image includes four full finger view images: one rolled; left, center, andright plain.
Condition in a compartment fire in which the entire volume is involved in combustion of varying intensities.
Operation of a mass spectrometer in which abundances of ions for entire mass spectrum arerecorded over a defined mass range.
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 waterproong material.
A device composed of a pyrotechnic mixture in a tube, usually equipped to be ignited by a mechanical initiation mechanism. DISCUSSIONThe 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 systems database, which typically contains all known-person biometric references (samples or templates, or both)
In facial identification, a FR system's database, which typically contains all known-person biometric refer- ences (samples or templates, or both).
The portion of the colorspace that can be represented or reproduced by a device or process
The portion of the colorspace that can be repre- sented 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.
A blended product used as a fuel in a spark ignited internal combustion engine. It is blended by a refinery from atmospheric distillation fractions, catalytic and hydro cracker products, alkylates, and other additives. It is chiefly composed of aromatic hydrocarbons, branched and some straight chain alkanes, and condensed ring aromatics. The abundance of aromatic compounds will typically be significantly greater that the other components. ASTM E1618-11 "Standard Test Method for Ignitable Liquid Residues in Extracts from Fire Debris Samples by Gas Chromatography-Mass Spectrometry" provides the minimum criteria for the identification of gasoline.