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 structure, part of a structure, or general geographic location within a fire scene, in which the 'point of origin' of a fire or explosion is reasonably believed to be located. (See also 3.3.149, Point of Origin.)
The act of using a canine to search a designated area for a target odor/scent.
Surface measurement method that produces a topographical image of a surface, which may berepresented mathematically as a height function z (x, y) of two independent variables (x, y).
a major group of unsaturated cyclic hydrocarbons containing one or more rings, typified by benzene, which has a 6-carbon ring containing nominally three double bonds.
A class of ignitable liquid characterized as being comprised almost exclusively of aromatic or condensed ring aromatic compounds, or both. Some examples of commercial products that may be in this class are: paint and varnish removers, insecticide carriers, auto parts cleaners and some specialty products.
a sharp line on the fracture surface defining the crack front shape of an arrested or momentarily-hesitated crack.
A condition in which the heart beats with an irregular or abnormal rhythm.
A condition in which the heart beats with an irregular or abnormal rhythm
A fire pattern displayed on the cross-section of a burned wooden structural member.
The crime of maliciously and intentionally, or recklessly, starting a fire or causing an explosion.
(1) A particular item or object, typically one of a specified type used to present to the canine for scent discrimination.(2) Scented objects left on the track or in a search area at various intervals to which the canine is expected to indicate.
(1) A particular item or object, typically one of a specified type used to present to the canine for scent discrimination.(2) Scented objects left on the track or in a search area at various intervals to which the canine is expected to indicate.
(1) A particular item or object, typically one of a specified type used to present to the canine for scent discrimination.(2) Scented objects left on the track or in a search area at various intervals to which the canine is expected to indicate.
(1) A particular item or object, typically one of a specified type used to present to the canine for scent discrimination. (2) Scented objects left on the track or in a search area at various intervals to which the canine is expected to indicate.
The process of locating and indicating items that contain non-specific or targeted human scent. (See evidence search.)
When a skeletal element forms a congruent joint or juncture with another element.
A non-allelic product of the amplification process (e.g., stutter, non-templated nucleotide addition, or other non-specific product), an anomaly of the detection process (e.g., pull-up or spike), or a byproduct of primer synthesis (e.g., 'dye blob') that may be observed on an electropherogram; some artifacts may complicate the interpretation of DNA profiles when they cannot be distinguished from the actual allele(s) from a particular sample.
Visual/aural aberration in an image, video, or audio recording resulting from a technical or operational limitation. DiscussionExamples include speckles in a scanned picture or blocking in images compressed using the JPEG standard.
A by-product, artificial feature, or change resulting from human activity or a technical process. (Compare noise.) DISCUSSION: Examples include speckles in a scanned picture, 'blocking' in compressed images, distortion in over-saturated audio, and the automatic creation of temporary files due to normal usage of a computer.
Distractions placed in the search area that do not occur naturally. (i.e., Proofing items such as containers, gloves that are not contaminated with human remains, uncontaminated storage containers etc.)
The American National Standard Code for Information Interchange.
The American Association of Crime Lab Directors.
The ratio of the width to the height of a rectangle, such as an image, a pixel, or an active video frame
The width-to-height ratio of a pixel or the captured image.
An evaluation during training and/or certification process; a tool to assess canine team ability.
An evaluation during training and/or certification process; a tool to assess canine team ability.
An evaluation during training and/or certification process; a tool to assess canine team ability.
An evaluation during training and/or certification process; a tool to assess canine team ability.
A record of the assessments of the canine team, i.e., evaluations during either the training or certification to access the canine teams ability and proficiency. The assessment records may be combined with training and certification records or maintained separately. A record documenting the performance of the canine team, especially an account of an act or occurrence kept in writing or some other permanent form, i.e., digital format, which is discoverable.
A record of the assessments of the canine team, i.e., evaluations during either the training or certification to access the canine teams ability and proficiency. The assessment records may be combined with training and certification records or maintained separately. A record documenting the performance of the canine team, especially an account of an act or occurrence kept in writing or some other permanent form, i.e., digital format, which is discoverable.
A record of the assessments of the canine team, i.e., evaluations during either the training or certification to access the canine team's ability and proficiency. The assessment records may be combined with training and certification records or maintained separately. A record documenting the performance of the canine team, especially an account of an act or occurrence kept in writing or some other permanent form, i.e., digital format, which is discoverable.
A record of the assessments of the canine team, i.e., evaluations during either the training or certification to access the canine team's ability and proficiency. The assessment records may be combined with training and certification records or maintained separately. A record documenting the performance of the canine team, especially an account of an act or occurrence kept in writing or some other permanent form, i.e., digital format, which is discoverable.
(See 3.16 certifying official).
A voice to which an identifier has been attached. The identifier may or may not pointto the person with that voice. For instance, the voice of an unknown speaker that hasbeen previously encountered can be considered an 'assigned voice' by attaching anidentifier to it in earlier transactions.
The result of a comparison between two hair samples in which the characteristics of the questioned hair are present in the known sample without any exclusionary differences, and therefore the donor of the known hair sample can be included as a possible source of the questioned hair. DiscussionA microscopical association of hair cannot identify the definitive source of a questioned hair to the exclusion of all others, and the number of individuals who could be included as a possible donor of a specific hair is unknown and cannot be reliably estimated.
the result of a comparison between two hair samples in which the characteristics of the questioned hair are present in the known hair sample without any exclusionary differences and, therefore, the donor of the known sample can be included as a possible source of the questioned hair.
Discussion—A microscopical association of hair cannot identify the definitive source of a questioned hair to the exclusion of all others and the number of individuals who could be included as a possible donor of a specific hair is unknown and cannot be reliably estimated.
A pathway laid by a human subject whose scent is associated with the scent on the article presented to the canine.
A pathway laid by a human subject whose scent is associated with the scent on the article presented to the canine.
A pathway laid by a human subject whose scent is associated with the scent on the article presented to the canine.
In facial identification, a submission of a single set of biometric samples to a biometric system for identification or verification. (Compare biometric search.)
a method of spectrophotometric analysis based on the reflection of energy at the interface of two media which have different refractive indices and are in intimate contact with each other.
An assertion, based on a decision following review, that specified requirements have been fulfilled.
The processing and filtering of audio recordings to improve the signal quality and intelligibility of the signals of interest, such as speech, by attenuating noise or otherwise increasing the signal-to-noise ratio