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.
of established origin associated with the matter under investigation.
Discussion—- Known soil samples are intentionally collected, typically from crime scene or alibi locations, for comparison to a questioned soil sample. Soils are heterogeneous mixtures of organic matter and minerals that vary with depth and across the landscape. Typically, more known samples are needed to represent the range of variation in soils than are required for manufactured materials.
An item of footwear or tire from a specific source that is compared to a questioned footwear or tire impression.
in facial identification and image analysis, an image of an individual or object associated with a known or claimed identity or object and recorded electronically or by other medium (also known as exemplars). (Compare questioned image.)
Biological material for which the identity of the donor is established and used for comparison purposes.
a coating sample of established origin.
known samples of geological material are intentionally collected, typically from crime scene or alternate locations, for comparison to a questioned sample.
Discussion—Geological materials are typically more heterogeneous than manufactured materials, so a greater number of known samples of geological material are needed to represent the range of variation (see Guide E3272). Reference sample and control sample are synonyms of known sample.
known soil samples are intentionally collected, typically from crime scene or alternate locations, for comparison to a questioned soil sample.
Discussion—Soils are heterogeneous mixtures of organic matter and minerals that vary vertically with depth and horizontally across the landscape. Typically, a greater number of known soil samples are needed than manufactured materials to represent the range of variation (see Guide E3272). Reference sample and control sample are synonyms or sub-types of known soil samples.
A voice signal from an individual who has been identified, or individuated in a waythat allows linking to additional, available information about that individual.
Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation, that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.
The entity providing the analysis, including the staff and the physical facility.
body that performs one or more of the following activities: testing; calibration; sampling, associated with subsequent testing or calibrationNote 1 to entry: In the context of this document, laboratory activities refer to the three above-mentionedactivities.
Point on a map where the person was last identified or spotted by a witness.
Learning that takes place unintentionally, and does not manifest in overt behavior at that time, but may become evident at a later stage.
An impression or image of friction ridge skin left on a surface.
Any public employee whose duties primarily involve the enforcement or investigation of alleged or suspected violations of law.
The systematic process of removing debris from the top down and observing the relative location of artifacts at the fire scene.
ammunition incorporating a primer that does not contain lead.
A period in which early progress in learning appears to have stopped and improvement is at a standstill. The plateau is followed by a new period of progress.
Indicates that the transaction element was valid in previous versions of the standard.Systems claiming conformance to this version of the standard shall only use the elementwhen transmitting information stored prior to the adoption of this version of the standard.
in facial identification, a verbal or numeric scale that indicates the level of confidence regarding identification or exclusion of a subject.
This characterizes the dispersion of values used for measuring dental age assessment based on the variation within the data.
An adhesive or other medium used to capture and preserve an impression.
A product of an EDD examination. The developed toner image on the imaging film is preserved by applying fixing film to create a lift.
a microscope that employs light in the visible portion of the electromagnetic spectrum.
in facial identification, an automated conclusion based upon threshold scores with no human involvement.
the majority non-carbohydrate portion of wood; it is an amorphous polymeric substance that cements cellulosic fibers together and is the principal constituent of woody cell walls.
A site designed to test the canine's ability to search and indicate independently of the handler.
An estimate of the lowest concentration of an analyte in a sample that can be reliably differentiated from blank matrix and identified by the analytical method.
An estimate of the lowest concentration of an analyte in a sample that can be reliably differentiatedfrom blank matrix and identified by the analytical method.
lowest amount of an analyte that is detectable with a given confidence level.
An estimate of the lowest concentration of an analyte in a sample that can be reliably differentiated from blank matrix and identified by the analytical method.
An estimate of the lowest concentration of an analyte in a sample that can be reliably differentiated from blank matrix and identified by the analytical method
An estimate of the lowest concentration of an analyte in a sample that can be reliably differentiated from blank matrix and identified by the analytical method.
An estimate of the lowest concentration of an analyte in a sample that can be reliably differentiated from blank matrix and meets identification criteria for the analytical method.
Quantification technique to estimate the actual number of individuals based on the number of paired and unpaired bones.
Utilization of a canine to scent discriminate among a predetermined sequence of items with target odor/scent(s) versus non-target odor/scent(s).
The borders defining the differences in fire effects on materials between the affected area and adjacent, less-affected areas.
Consists of finding the best-fit linear relationship between the instrument response (Y) and the concentration of the analyte in the calibrator (X)
Document(s) exposed to or immersed in liquid(s).
Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose.
the time during which an energy dispersive X-ray spectrometer is available to accept and process incoming X-rays.
Discussion—Live time is often expressed as a percentage of real time, in seconds.