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.
Hybrid Mixture
An explosible heterogeneous mixture, comprising gas with suspended solid or liquid particulates, in which the total flammable gas concentration is 10 percent of the lower flammable limit (LFL) and the total suspended particulate concentration is 10 percent of the minimum explosible concentration (MEC). [68, 2018]
hybridization
Interbreeding between two taxa that are considered to have diverged in their genetic makeup and taxonomic relationship (e.g., between members of different families, genera, or species). Hybridization commonly occurs between subspecies or closely related species.
Hypergolic
Hypergolic
Hypergolic Material
Any substance that will spontaneously ignite or explode upon exposure to an oxidizer.
Hypervariable Region
A segment of DNA that often contains polymorphisms and thus is useful for differentiating taxa or unrelated individuals.
Hypervariable Region 1 (Hv1)
A section of the human mtDNA control region spanning nucleotide positions 16024-16365, that often differs among non-maternally related individuals.
Hypervariable Region 1 (Hvi)
A section of the human mtDNA control region spanning nucleotide positions 16024-16365, that often differs among non-maternally related individuals.
Hypervariable Region 2 (Hv2)
A section of the human mtDNA control region spanning nucleotide positions 73-340, that often differs among non-maternally related individuals.
Hypervariable Region 2 (Hvii)
A section of the human mtDNA control region spanning nucleotide positions 73-340, that often differs among non-maternally related individuals.
Hz
Abbreviation for Hertz, which is the measure of the frequency of oscillations. It is thefundamental property of sound that determines pitch.
Hz
Hertz is the international unit of measurement of frequency. One hertz corresponds to one cycle per second.
IAFIS
Acronym for the Integrated Automated Fingerprint Identification System of the FBI.
IAP
Acronym for Iris Acquisition Profile. It is a series of sets of progressively morestringent parameters and requirements relevant to iris acquisition. [2015a>] In theMobile ID Best Practices Recommendations Version 1, face, finger and iris applicationprofiles were all referred to as SAP. They are referred to separately in this standard.This was changed in Mobile ID Best Practices Recommendations Version 2 to beconsistent with this standard.
IBIA
International Biometric Industry Association.
ICAO
The International Civil Aviation Organization.
ICC
International Color Consortium.
Identifiable Human Group
A population of individuals based on ancestry or population specificity that reflects a similar genetic, geographic, and environmental background.
identification
Assignment to the most specific class attainable
NOTE In forensic toxicology, identification refers to determining the presence of drugs, chemicals, or toxins within a biological sample.
Identification
OSAC Preferred
Assignment or distinguishment of an unknown object, compound, biological sample, or other evidence to the most specific class or level reliably attainable under the analytical scheme used.
NOTE: Uncertainty and limitations always remain in any finding
NOTE: Presence of this term in the OSAC Lexicon does not endorse its use in place of relevant interpretation scale levels for the discipline or method
NOTE: Although this term is used informally, the term should not be used in written or oral interpretations or opinions for any discipline for conveying source of the evidence.
Also referenced in ASB TR 097, Terminology Used for Forensic Footwear and Tire Evidence, ANSI/ASTM E1732-24e1 Standard Terminology Relating to Forensic Science.
identification document
Made or issued by or under the authority of a governmental or private organization which, when completed with information concerning a particular individual, is of a type intended or commonly accepted for the purpose of identification of individuals.
IEC
The International Electrotechnical Commission.
IED
Improvised Explosive Device
Ignitable Liquid
Any liquid or the liquid phase of any material that is capable of fueling a fire, including a flammable liquid, combustible liquid, or any other material that can be liquefied and burned.
Ignitable Liquid
Ignitable Liquid Detection Canine Igl
Canines specifically trained to locate and respond to the presence of certain classes of ignitable liquids by associated odor. Also known as accelerant detector canine or arson dog.
Ignitable Liquid Residue(s) (ILR)
Ignitible Liquid
Any combustible or flammable liquid.
Ignitible Liquid Detection Canines (Igl Canines)
Ignitible liquid detection canines (IGL canines) are dogs specifically trained to locate and respond to the presence of certain classes of ignitible liquids by associated odor.
Ignition
The process of initiating self-sustained combustion.
Ignition Energy
The quantity of heat energy that should be absorbed by a substance to ignite and burn.
Ignition Susceptibility Test (IST)
Ignition Temperature
Minimum temperature a substance should attain in order to ignite under specific test conditions.
Ignition Time
The time between the application of an ignition source to a material and the onset of self-sustained combustion.
ILAC
International Laboratory Accreditation Cooperation.
Illicit Drugs
Substances used non-medically that are prohibited by law, including but not limited to stimulants, cannabis, cocaine, heroin, other opioids, and MDMA.
Image
Image
image
A visually observable counterpart of an object produced by means of imaging technology. (SWGDOC D01)
Image Analysis
image area
That portion of the page that is printed, including the space between letters and lines. (ASTM F1457)
Image Averaging
Image Comparison, Photographic Comparison
Image Content Analysis
Image Data Recovery
image density
Contrast between image and background as measured by densitometer. (ASTM F221)
Image Enhancement
image enhancement
Any process intended to improve the visual appearance of an image or specific features within an image. (ASTM E2916)
image formation
The elements that comprise an image to include, but not limited to, continuous inked areas, halftone patterns, and dot characteristics.