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.
broad, flat, elongated crystals.
Any area or container where target odor/scent is not present. (See blank search.)
a control where a specified component(s) is not present.
Discussion—Blanks with various designations can be specified, such as system blank, process blank, method blank, reagent blank, solvent blank, etc. Certain blanks may also serve as a negative control.
A biological fluid or tissue (or synthetic substitute) without target analyte or internal standard
A training or certification exercise in which the target scent is not present.
A training or certification exercise in which the target scent is not present.
A training or certification exercise in which the target scent is not present.
A training or certification exercise in which the target odor/scent is not present.
A known odor/scent sample that is used to assess the canine's proficiency in a non-matching odor/scent scenario. The canine is expected to give a negative response.
a non-detonator sensitive explosive that must be initiated by a booster, or that requires a primer to detonate.
Discussion—Many ammonium nitrate-based explosives fall into this category.
a cylindrical shell, usually of metal, containing both a primary high explosive and a secondary high explosive, which is used to initiate other explosives; also known as a detonator or cap.
The expanding leading edge of an explosion reaction that separates a major difference in pressure between normal ambient pressure ahead of the front and potentially damaging high pressure at and behind the front.
Boiling liquid expanding vapor explosion.
The process of withholding information that may bias the forensic dental age assessment practitioner.
The person(s) obtaining the measurements does not know the treatments.
A type of verification in which the subsequent examiner(s) has no knowledge of any other examiner’s decisions, conclusions or observed data used to support the conclusion.
A panel of blood tests that measures the components of blood including electrolytes, glucose and enzymes that provides information about organ function and physiologic state.
A panel of blood tests that measures the components of blood including electrolytes, glucose and enzymes that provides information about organ function and physiologic state.
An individual who has completed the prescribed course of study.
An estimate of the total drug in the body based on quantitative analysis of blood, urine, and/or tissue samples
Weight for frame and relative proportions of muscle and fat.
Weight for frame and relative proportions of muscle and fat.
The process of evaluating the relative fat composition of the canine. Scores are based on 1 to 5 with normal as a 2 to 3; or 1 to 9 with normal as a 4 to 5.
The process of evaluating the relative fat composition of the canine. Scores are based on 1 to 5 with normal as a 2-3; or 1-9 with normal as a 4-5.
Fluids associated with a human body (e.g., sweat, saliva, blood, vomit, decomposition fluids).
an explosive device, usually some kind of container filled with explosive, incendiary material, gas, or other destructive substance, designed to cause damage by way of thermal, blast, or fragmentation effects on impact or when detonated by a time mechanism, switch, remote control device, electric match, or lit fuse.
Positive relationship, rapport between canines or a human(s) and a canine.
The permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed.
A piece of shaped bone or other material, such as plastic or non-stick material, typically used by bookbinders to crease paper and to separate pieces of paper that are stuck together.
a device with a hidden or concealed triggering mechanism designed to be initiated by the victim; also known as a victim-activated device.
a detonator-sensitive high explosive charge used to initiate a main-charge explosive that is usually detonator insensitive.
Checking to confirm expected outputs are obtained when inputs are at the limits of the software (e.g., testing allele frequencies below the 5/2N minimum threshold or testing upper and lower limits for amplification setup calculations).
ignition component consisting of a cup, explosive mixture, anvil, and covering foil or paper disk that together form the completed primer ready for assembly into the primer pocket of a cartridge case.
describes the physical phenomenon of X-ray scattering from a crystallographic three-dimensional lattice plane as nλ=2dsinθ, in which n is any integer, λ is the wavelength of the X-ray, d is the crystal plane separation, also known as d-spacing, and θ is the angle between the crystal plane and the diffracted beam, also known as the Bragg Angle.
the intertwining of strands in a braiding process to produce a rope structure.
a subclass of aliphatic hydrocarbons with the general formula CnH2n+2, with subordinate chains branching off of the main chain; also known as isoparaffin and isoalkane.
a subclass of aliphatic hydrocarbons with the general formula CnH2n+2, with subordinate chains branching off of the main chain; also known as isoparaffin and isoalkane.
organizational structure including policies, procedures, responsibilities, and resources necessary for implementing core breath alcohol activities. Activities include, but may not be limited to, requirements or specifications for reference material, training of operators, maintenance and calibration of instrumentation, the evidential breath alcohol test sequence, and record retention.
An organizational structure including policies, procedures, responsibilities and resources necessary for implementing core breath alcohol activities. NOTE The Breath Alcohol Program includes, but may not be limited to, requirements or specifications for reference materials, training of operators, maintenance and calibration of instrumentation, the evidential breath alcohol test sequence, and record retention.
A signal (conditioned reinforcer) that marks (reinforces) a desired behavior. Often called a bridge because it bridges the gap in time from when the animal performs the desired behavior to when it receives the reward. An example would be the use of a clicker.
the ability of an explosive to shatter an object when fired in direct contact or in its vicinity.
The quantity of heat required to raise the temperature of one pound of water 1F at the pressure of 1 atmosphere and temperature of 60F; a British thermal unit is equal to 1055 joules, 1.055 kilojoules, and 252.15 calories