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 characteristic change in ongoing behavior in response to a trained scent, as recognized by the canine handler. The components of the alert may include: change of behavior (COB), interest, and final response or indication. (See 3.31 final response.)
A characteristic change in ongoing behavior in response to a trained scent, as recognized by the canine handler. The components of the alert may include: change of behavior (COB), interest, and final response or indication. (See 3.31 final response.)
a known location suggested or linked to a subject (for example, a subject's home) that is distinct from the crime scene.
Discussion—The term alibi or alibi location can be perceived negatively, but comparisons of geological materials from alibi locations can be exonerating. Alibi location is used in this document to be succinct, however use of this term in documentation of evidence, evidence examination reports, or courtroom testimony is discouraged.
An arrangement of two or more nucleotide or protein sequences that is used to illustrate similarity among those sequences.
descriptive of one of the major groups of organic compounds, characterized by normal, branched-, or cyclic chain arrangement of the constituent carbon atoms, but does not include aromatic compounds.
descriptive of one of the major groups of organic compounds, characterized by normal, branched-, or cyclic chain arrangement of the constituent carbon atoms, but does not include aromatic compounds.
a class of unsaturated aliphatic hydrocarbons having two double bonds; also known as diene.
a class of unsaturated aliphatic hydrocarbons having two double bonds; also known as diene.
a class of aliphatic hydrocarbons characterized by a straight or branched carbon chain; generic formula CnH2n+2; also known as paraffin.
Discussion—In the plural form, also sometimes used to refer to the general class of aliphatic compounds that includes branched, normal, and cycloalkanes.
a class of unsaturated aliphatic hydrocarbons having one or more double bond(s); also known as olefin.
Discussion—In the plural form, also sometimes used in fire debris analysis to refer to the general class of aliphatic compounds with one or more double bonds.
a class of unsaturated aliphatic hydrocarbons hav- ing one or more double bond(s); also known as olefin.
DISCUSSION—In the plural form, also sometimes used in fire debris analysis to refer to the general class of aliphatic compounds with one or more double bonds.
One member of a series of possible alternative forms of a DNA sequence found at aparticular genetic location.
One of two or more versions of a genetic sequence at a particular location in the genome.
One of two or more versions of a genetic sequence at a particular location (a locus) in a genome.
The value identified for the allele, either via expert system or by an analyst.
in computer forensics, the portions of storage that are assigned or reserved for active instructions or for data.
a solid or liquid mixture of two or more metals, or of one or more metals with certain non-metallic elements, as in carbon steels.
A modification made to a document by any combination of physical, chemical, or mechanical means including, but not limited to, obliterations, additions, overwritings, or erasures.
The result of changing something.
Equipment used to produce light at various wavelengths to enhance or visualize potential items ofevidence.
Equipment used to produce light (or to restrict light) at various wavelengths to enhance orvisualize potential items of evidence
Equipment used to produce light at various wavelengths to enhance or visualize potential items of evidence.
Equipment used to produce light at various wavelengths to enhance or visualize potential items of evidence.
NOTE A monochromatic light source can be used in examination of an animal’s body to enhance visualization, identification, documentation, and collection of bodily fluids and fibers as potential evidence.
Someone's or something's surroundings, especially as they pertain to the local environment; for example, ambient air and ambient temperature.
A report used to document any subsequent modifications, particularly those that affect or correct an original result or interpretation
A report used to document any modifications from a previously issued report, particularly those that affect or correct an original result or interpretation.
A voluntary national, not-for-profit, independent professional certification board that has been established to promote the highest standards of practice for medicolegal death investigators (see www.abmdi.org).
The United States' largest dental association and the leading source of oral health-related information for dentists and their patients
The maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
The unit of electric current that is equivalent to a flow of one coulomb per second; one coulomb is defined as 6.24 _ 1018 electrons.
Any PCR amplification product.
An increase in the number of copies of a specific DNA fragment. In forensic DNA testing laboratories, this refers to the use of the PCR technique to produce many more copies of fragments at specific genetic loci from samples of known and unknown origin for the purpose of generating DNA profiles for comparison.
An increase in the number of copies of a specific DNA fragment; can be in vivo or in vitro. In forensic DNA testing laboratories, this refers to the use of the PCR technique to produce many more copies of DNA at specific genetic loci.
The process by which the number of copies of a specific DNA fragment is increased.
An increase in the number of copies of a specific DNA fragment; can be in vivo or in vitro. In forensic DNA testing laboratories, this refers to the use of the PCR technique to produce many more copies of DNA at specific genetic loci.
the active growth phase of a hair follicle in the hair growth cycle.
Discussion—The root from a pulled anagen hair is elongated and is usually fully pigmented.
Consists of the assessment and documentation of the quality and quantity of the observed class characteristics and characteristics of use of an unknown impression and known footwear or tire.
The interpretation of observed data in a friction ridge impression in order to categorize its utility.
The interpretation of observed data in a friction ridge impression in order to categorize its utility.
The interpretation of observed data in a friction ridge impression in order to categorize its suitability/utility.
A qualified individual who conducts and/or directs the analysis of forensic casework samples, interprets data, reaches conclusions, and/or issues reports concerning conclusions.
A qualified individual who conducts and/or directs the analysis of forensic casework samples, interprets data, reaches conclusions, and/or issues reports concerning conclusions.
A chemical substance to be identified and/or measured.
Includes all targeted compounds in a screening assay, as well as compounds being quantitated and/or confirmed
A set of standards, controls, and/or case samples that are contemporaneously prepared and/or analyzed a particular sequence..
Set of standards, controls, and/or case samples that are contemporaneously prepared and/or analyzed in a particular sequence
A selection of drugs, drug metabolites, and other chemicals covered in an analytical testing scheme.
A selection of drugs, drug metabolites, and other chemicals covered in an analytical testing scheme.