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 decision which identifies an organism as the source of the DNA that produced an evidentiary single-source or major contributor profile; This statement is often based on population frequency estimates that are more rare than some defined number.
Specially designed portion of a checkwriter impression immediately preceding that of the collective segments or the machine part from which the designed impression is created.
a term indicating an individual can be discriminated to the exclusion of all other sources.
Discussion—Hairs cannot be individualized by means of microscopical hair comparison.
The process by which a person starts from a particular experience and proceeds to generalizations. The process by which hypotheses are developed based upon observable or known facts and the training, experience, knowledge, and expertise of the observer.
The analysis of specimens from children or their caregivers in cases of suspected exposure to harmful substances.
The interval in human dental development that begins at birth, includes the presence of the developing, developed and resorbing primary dentition as well as the initial development of the permanent dentition. This interval includes the early period of mixed primary and permanent dentitions and ends when the last primary tooth is exfoliated normally. Note 1 to entry: During the adolescent age and adult dental age intervals, primary teeth may be atypically retained for various reasons, including congenital absence or ectopic eruption of the permanent teeth that would typically replace them.
Referring to radiant flux having wavelengths longer than the wavelengths of visible light, usually from ~700 nm to 1400 nm (~0.7 μm to 1.4 μm) as per the International Commission on Illumination (CIE) for IR-A.
The emission of radiant energy during a transition from an excited electronic state of an atom, molecule, or ion to a lower electronic state (fluorescence or phosphorescence, or both), where the spectrum of the excitation source is in the ultraviolet (UV) or visible region of the electromagnetic spectrum, or both, and the spectrum of the emitted energy is in the far red or infrared (IR) region of the electromagnetic spectrum.
As related to the polymerase chain reaction (PCR), any substance that interferes with or prevents the synthesis of DNA during the amplification process.
The fundamental training associated with detector canine training which consists of, but not limited to: bonding/relationship building, obedience, basic odor/scent discrimination, and basic search techniques.
The fundamental training associated with detector canine training which consists of, but not limited to: bonding/relationship building, obedience, basic odor/scent discrimination, and basic search techniques.
The fundamental training associated with detector canine training which consists of, but not limited to: bonding/relationship building, obedience, basic odor/scent discrimination, and basic search techniques.
The fundamental training associated with detector canine training which consists of, but not limited to: bonding/relationship building, obedience, basic scent discrimination, and basic search techniques.
The fundamental training associated with detector canine training which consists of, but not limited to: bonding/relationship building, obedience, basic scent discrimination, and basic search techniques.
The fundamental training associated with detector canine training which consists of, but not limited to: bonding/relationship building, obedience, basic scent discrimination, and basic search techniques.
primary explosive that will explode or detonate when heated or subjected to shock.
Discussion—Examples include lead styphnate, mercury fulminate, lead azide, and silver fulminate.
the device which initiates an explosive train; starting an explosion.
A chemically infused commercial product used to coat tread in order for the tread pattern to be captured onto chemically treated paper.
the border between the cortex and the visible cuticle.
a class of fibers of natural mineral origin (for example, chrysotile asbestos) and manufactured mineral origin (for example, fiberglass).
that portion of GSR coming from metals as vaporous material from the bullet, cartridge case, and primer.
examination of a product (3.2), process (3.3), service (3.4), or installation or their design and determinationof its conformity with specific requirements or, on the basis of professional judgment, with generalrequirementsNOTE 1 Inspection of processes can include personnel, facilities, technology or methodology.NOTE 2 Inspection procedures or schemes can restrict inspection to examination only.NOTE 3 Adapted from ISO/IEC 17000:2004, definition 4.3.NOTE 4 The term item is used in this International Standard to encompass product, process, service or installation,as appropriate.
Examination of a «product» (3.2), «process» (3.3), «service» (3.4), or installation or their design and determination of its conformity with specific requirements or, on the basis of professional judgment, with general requirements
body that performs inspection (3.1)NOTE An inspection body can be an organization, or part of an organization.
Body that performs «inspection» (3.1)
(3.6) to which the same specified requirements, specific rules and procedures applyNOTE 1 Inspection schemes can be operated at international, regional, national or sub-national level.NOTE 2 Schemes are sometimes also referred to as programmes.NOTE 3 Adapted from ISO/IEC 17000:2004, definition 2.8.
Inspection system (3.6) to which the same specified requirements, specific rules and procedures apply
rules, procedures, and management for carrying out inspectionNOTE 1 An inspection system can be operated at international, regional, national or sub-national level.NOTE 2 Adapted from ISO/IEC 17000:2004, definition 2.7.
Rules, procedures, and management for carrying out inspection
An XML package described by a schema is called an instance document. If a documentsatisfies all the constraints specified by the schema, it is considered to be schema-valid.
The innate tendency to react in specific ways in specific circumstances. Behaviors that are not taught, and are stereotypical in action and similar in all members of a species.
See canine trainer.
equipment capable of performing measurements used to generate analytical data (for example, GC-MS, IR, NMR, balances, etc.).
See operant conditioning.
The INTERPOL application profile of the ANSI/NIST-ITL standard, developed by theINTERPOL AFIS Expert Group.
an explosive that has not undergone decomposition due to deflagration or detonation and generally has a discernible morphology.
Discussion—Intact explosives can be present in large (grams) or small (single particle) quantities. Post-blast explosive residues can contain both combustion products and intact explosive material.
a process of confirming that the data presented is complete and unaltered since time of acquisition.
The extent to which different observers obtain the same result when measuring the same behavior.
The portion of the palm along the base of the fingers.
Any reaction to an odor/scent, which may include: (1) A noticeable, readable, physical change in behavior in a detector canine during the search when the canine reacts to (i.e., is interested in) an odor/scent. (2) Pattern of behavior following the canine's initial reaction to a trained odor/scent when the canine displays motivation to remain at or trace the trained odor/scent to its source. (See change of behavior.)
Any person, entity, or organization, including their representatives, with statutory obligations or whose legal rights or interests may be affected by the investigation of a specific incident.
the temperature of the heated zone between the pyrolysis unit and the GC.
colors produced by the interference of two out-of-phase rays of white light when a birefringent material is observed at a non-extinction position between crossed polars.
Discussion—The retardation at a particular point in a birefringent fiber can be determined by comparing the observed interference color to the Michel-Lévy chart.
pattern observed during conoscopic observation of an anisotropic material which consists of a combination of extinction positions and interference colors corresponding to the full cone of directions by which the sample is illuminated.
DISCUSSION—Conoscopic observations are typically made by insert- ing a Bertrand lens into the body tube or by removing an eyepiece and viewing down the body tube.
the pattern that results from constructive and destructive interference of light waves.
Experiments performed to determine substances that inhibit or affect the intensity of the assay signal.
Non-targeted substances (i.e., matrix components, other drugs and metabolites, internal standard, impurities) which may impact the ability to detect, identify, or quantitate a targeted analyte.