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.
angle of incidence
The angle formed between the nominal path of a projectile and the plane of the target (also referred to as angle of impact).
animal
A creature or living being, other than human. The legal definition of animal may be further defined by local law.
Anion
Anisotropic
anomalous interference colors
atypical polarization colors which occur due to variation with wavelength of the refractive index (very few substances display this characteristic).
anomaly
A deviation from typical skeletal anatomy; often nonlethal or nondisruptive to function; it may or may not have clinical or forensic significance.
anomaly
A deviation from typical anatomy; often non-lethal or non-disruptive to function; it may or may not have clinical or forensic significance.
ANSI
The American National Standards Institute, Inc.
Antemortem
Prior to death.
antemortem skeletal feature
A skeletal condition, defect, or anomaly that occurred before an individual’s death, with evidence of a biological reaction.
antemortem trauma
A skeletal defect that occurred before an individual’s death and shows evidence of osteological reaction.
Anthropogenic
Relating to having origins in human activity.
Anthropometric Analysis
Anti-Forensics
anti-stokes luminescence
Photoluminescence whose radiation is located in a spectral region of shorter wavelengths than that of the exciting radiation. NOTE This happens, for instance, when the energy of the emitted photons originates from the absorption of two exciting photons. (CIE S 017/E:2011 ILV)
Aperture
Aperture
apex
The uppermost point of a character. (SWGDOC T01)
Appeal
request by the provider of the item of inspection to the inspection body for reconsideration by that body of adecision it has made relating to that itemNOTE Adapted from ISO/IEC 17000:2004, definition 6.4.
Appeal
A request by a forensic science service provider to the inspection body for reconsideration by that body of a decision, finding, or other action.
appeal
request by the client (3.7) to an inspection body (3.2) for reconsideration by that body of a decision it has made relating to the conformity of the item (3.8) inspected
Note 1 to entry: An appeal is only possible if a statement of conformity has been issued.
[SOURCE: ISO/IEC 17000:2020, 8.6, modified — In the definition, "person or organization that provides, or that is, the object of conformity assessment to a conformity assessment body or an accreditation body" has been replaced by "client to an inspection body"; "that object" has been replaced by "the conformity of the item inspected"; Note 1 to entry has been added.]
Appendix F Certified Devices
This refers to devices that have successfully completed a test of fingerprint capture devices that is performed in accordance with procedures established by the FBI in EBTS Appendix F. [2013a]
apprentice
A student under in-person, direct supervision of a principal trainer on an almost daily basis. There may or may not be a financial arrangement between the trainer and apprentice.
Apprenticeship
apprenticeship
An arrangement in which a student is learning knowledge, skills, and abilities through practical experience under a skilled worker(s).
Approval
Permission for a product or process to be marketed or used for stated purposes or under stated conditions. Approval can be based on fulfillment of specified requirements or completion of specified procedures.
Approved
Acceptable to the authority having jurisdiction
Approved
Acceptable to the authority having jurisdiction
Approximation
See shaping.
Arc
A high-temperature luminous electric discharge across a gap or through a medium such as charred insulation.
Arc Mapping
Identifying and documenting a fire pattern derived from the identification of arc sites used to aid in determining the area of fire origin or spread.
Arc Melting
Melting of conductors and conducting surfaces as a result of electrical arcing. The characteristics of arc melting are described in 9.11.1.1.
Arc Site
The location on a conductor with localized damage that resulted from an electrical arc.
arcade
Stroke used to form the arcs of the cursive letters m and n; also a cursive writing style where upward arc forms predominate. May be referred to as over curve.
Archive Image
Arcing Through Char
Arcing associated with a matrix of charred material (e.g., charred conductor insulation) that acts as a semiconductive medium.
Area Of Convergence
area of expertise
discipline in which an examiner is competent
Area Of Origin
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.)
Area Of Origin
Area Search
The act of using a canine to search a designated area for a target odor/scent.
Areal-Topography Method
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).
arm
A stroke that is attached at one end to another portion of the character such as that in the upper right portion of the upper case "K".
Aromatic
arrangement (general)
The placement of handwritten or printed text on the page, including characteristics such as margins, interline and inter-word spacing, indentations, and paragraphing. (based on NIST HF)
Arrest Lines
Arrhythmia
A condition in which the heart beats with an irregular or abnormal rhythm
Arrow Pattern
A fire pattern displayed on the cross-section of a burned wooden structural member.
Arson
The crime of maliciously and intentionally, or recklessly, starting a fire or causing an explosion.
Article
(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.