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 positive control that is diluted in the same manner as the diluted case sample(s)
A manufacturing process where the upper of the footwear is joined to the midsole or outsole material.
The route in which a subject laid a trail as indicated by the canine.
The route in which a subject laid a trail as indicated by the canine.
The angle (gamma) between the long axis of a splatter stain and a defined reference line on the target.
The control a canine handler has over the canine during a search whereby the canine handler directs the canine into productive search areas by utilizing hand or voice cues.
A tire tread pattern that is designed or intended to rotate in one direction only.
The characteristic of a bloodstain that indicates the direction blood was moving at the time of deposition.
In computer forensics, an object or structure used to group files together within a filesystem.
In computer forensics, an object or structure used to group files together within a filesystem
In computer forensics, a list of files and, optionally, file properties contained within a filesystem.
In computer forensics, a list of files and, optionally, file properties contained within a filesystem
A record of the deployment and/or utilization of a trained canine team, maintained separately from other records, i.e., training, assessments or certifications. A record documenting the deployment and/or utilization of the canine team, especially an account of an act or occurrence kept in writing or some other permanent form, i.e., electronic format, which is discoverable. (See record, deployment record or utilization record.)
A record of the use of a trained canine team in an operational environment, as opposed to training records. A log constituting a piece of evidence about the past, especially an account of an act or occurrence kept in writing or some other permanent form, i.e., digital format. A log record of the use of a trained canine team in an operational environment, as opposed to training records (also called record, utilization log and record, and discipline-specific deployment log).
Documentation that pertains to an investigation that can be requested and must be produced by the prosecution or the defense for trial purposes. For example, notes, records, certifications, photographs or digital media.
Documentation that pertains to an investigation that can be requested and must be produced by the prosecution or the defense for trial purposes. For example, notes, records, certifications, photographs or digital media.
To distinguish between two samples based on meaningful differences; to differentiate
To distinguish between two samples based on meaningful differences; to differentiate
The ability of an analytical procedure to distinguish between two items of different origin
The ability of an analytical procedure to distinguish between two items of different origin.
The ability to recognize differences between two or more stimuli. Operational usage: The ability to recognize differences between two or more odors/scents.
The ability to recognize differences between two or more stimuli. Operational usage: The ability to recognize differences between two or more scents.
A stimulus that signals when a particular response produces specific consequences. For example, sitting in the presence of a particular odor/scent leads to a reward. The odor/scent in this case is the discriminative stimulus.
distinct features that occur in natural fibers (for example, flax, ramie, jute, hemp) in the shape of Xs, Is, and Vs that are present along the fiber cell wall; these features are often useful for identification.
Distinct features that occur in natural fibers (for example, flax, ramie, jute, hemp) in the shape of Xs, Is, and Vs that are present along the fiber cell wall; these features are often useful for identification
The variation of birefringence with wavelength of light
an optical staining technique in which colors are produced by the differential refraction of different wavelengths of light due to mounting the sample in a liquid having a different dispersion of refractive index.
An optical staining technique in which colors are produced by the differential refraction of different wavelengths of light due to mounting the sample in a liquid having a different dispersion of refractive index
the variation of birefringence with wavelength of light.
A feature in an impression having the appearance of potentially originating from a different shoe or tire but lacking sufficient detail for confirmation.
the end of the hair farthest away from the root.
the end of the hair farthest away from the root.
The segment of a finger or thumb farthest from the palm.
A highly contagious viral disease of canids, including domestic canines, that is caused by a paramyxovirus genus Morbillivirus) and is marked by fever, leukopenia, and respiratory, gastrointestinal, and neurological symptoms, especially in young canines. In older canines symptomology may be less severe, but neurological impairment is always common.
a physical separation based on the vaporization of the different components of the mixture to be separated.
An unclear or inaccurate representation of the footwear or tire in an impression due to interference in the impression-making process or its subsequent retrieval
The tendency to be easily diverted from task.
Meaningful or meaning less blank-target sources that prevent concentration or diverts attention.
Non-target stimuli placed within a search area. These can include: humans, toys, food, animal odor, etc.
Non-target stimuli placed or naturally occurring within a search area. These can include: humans, toys, food, animal odor, etc.
Non-target stimuli placed or naturally occurring within a search area. These can include: humans, toys, food, animal odor, etc.
Non-target stimuli placed or naturally occurring within a search area. These can include: humans, toys, food, animal odor, etc.
Non-target stimuli placed or naturally occurring within a search area. These can include: humans, toys, food, animal odor, etc.
Non-target stimuli placed within a search area. These can include: humans, toys, food, animal odors or other blank-target odors/scents.
Intentional paralyzing of a computer or a computer network by flooding it with data sent simultaneously from many locations
A change in the normal odor/scent picture of the area.
An abbreviation for maximum density. The abbreviation is used in describing both the characteristics of an image and/or an imaging device such as a scanner.
Department of Motor Vehicles or Division of Motor Vehicles
Deoxyribonucleic Acid. This is a chemical that forms a double helix that is unique to allbut identical siblings.
Deoxyribonucleic acid