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.
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.
The entity providing the analysis, including the staff and the physical facility.
Process of stamp manufacturing using “laserable rubber” (pre-vulcanized natural rubber) and laser engraving to cut the image to form the die of the stamp.
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.
This characterizes the dispersion of values used for measuring dental age assessment based on the variation within the data.
in facial identification, a verbal or numeric scale that indicates the level of confidence regarding identification or exclusion of a subject.
A product of an EDD examination. The developed toner image on the imaging film is preserved by applying fixing film to create a lift.
An adhesive or other medium used to capture and preserve an impression.
Use of a xenon flash in the manufacturing of a flat die stamp. Numerous light bursts are used to seal the background of the stamp pad leaving open micropores in the area of the flat die to print the text.
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.
The probability of the evidence under one proposition (hypothesis), divided by the probability of the evidence under an alternative, mutually exclusive proposition (hypothesis). The magnitude of its value expresses the weight of the evidence.
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.
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 identified by the analytical method.
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
Estimate of the lowest concentration of an analyte in a sample that can be reliably differentiated from blank matrix and meets identification criteria.
lowest amount of an analyte that is detectable with a given confidence level.
1) For a test, the point at which the sensitivity of the test is such that the quantity or concentration of a component present is insufficient to produce a positive test result or be detected. 2) For instrumental analysis, the point below which it is not possible to reliably distinguish analytical signal data from instrument background noise; typically defined as three times the standard deviation of the average background noise; The LOD may be calculated to aid in setting an analytical threshold for the reporting and interpretation of alleles in a DNA profile electropherogram.
A site designed to test the canine's ability to search and indicate independently of the handler.
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).
Consists of finding the best-fit linear relationship between the instrument response (Y) and the concentration of the analyte in the calibrator (X)
Method of estimating stature based on a statistical procedure for describing a relationship between stature and bone dimension that can be used to predict the former from the latter.
The borders defining the differences in fire effects on materials between the affected area and adjacent, less-affected areas.
The nonrandom association, in a population, of alleles at different loci.
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 over which the energy dispersive X-ray spectroscopy electronics are available to accept and process incoming X-rays. Live time is often expressed as a percentage of real time.
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.
A person’s recorded height, which may be derived from various sources including self-reported stature, family remembrance, or direct measurement.
Utilization of a trailing canine to determine if a matching scent is located at a specific site or not by using a scent article.
Utilization of a trailing canine to determine if an associated scent is located at a specific site or not by using a scent article.
A test involving one odor per 0.3 meters (1 foot), 1 minute per odor.