OSAC Lexicon

Any public employee whose duties primarily involve enforcement or investigation of laws.

The systematic process of removing debris from the top down and observing the relative location of artifacts at the fire scene.

A visible, thin, elongated deposition of bullet wipe transferred to a surface as a bullet first makes contact with that surface at a shallow angle of incidence. 

NOTE The lead-in mark is useful in establishing the entrance side of the projectile impact.

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.

A large appendage typically on the right side of such characters as "R" and "K", usually formed with a downward movement.

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.

Relief printing using cast metal type, molded duplicate plates, or photo-polymer plates, which the imaged areas are raised above the non-printing areas, resulting in characters impressed into the substrate.

This characterizes the dispersion of values used for measuring dental age assessment based on the variation within the data.

A product of an EDD examination. The developed image on the imaging film is preserved by applying fixing film to create a lift. (ANSI/ASB Std 044)

The removal of one or more images of copy from the substrate by transferring to an intermediate member. (ASTM F221)

The removal of a typed character by restriking with the same character while interposing an adhesive coated tape or sheet, thereby causing the imprinted character to adhere to the coating and be stripped from the record medium; then the intended character or space is placed therein.

In printing or writing, two or three characters linked to create a single letterform such that the terminal stroke of the first is the initial stroke of the second.

Credit: Academy Standards Board

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.

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 for the analytical method

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 constraint to the examination, comparison, or opinion formation process (e.g., non-original documents, insufficient quantity or quality of material).

A site designed to test the canine's ability to search and indicate independently of the handler.

Limited examinations are partial analyses, comparisons, and/or processing that do not fully utilize the capabilities of a Forensic Service Provider (FSP).

Quantification technique to estimate the actual number of individuals based on the number of paired and unpaired bones.

Uninterrupted writing. Discontinuity may be in the form of pen lifts, pen stops, hesitations, or patching.

The appearance of the written stroke caused by the basic movements and the manner of manipulating the writing instrument. Results from the combination of such factors as speed, rhythm, shading, and smoothness of movement. It may vary from good line quality that is smooth and fluent to poor line quality that is tremulous and erratic.

The distance between successive lines of text, which for machine-generated documents is usually measured from baseline to baseline.

Utilization of a canine to scent discriminate among a predetermined sequence of items with target odor/scent(s) versus non-target odor/scent(s).

linear regression method 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. 

NOTE This definition is derived from ANSI/ASB Std 045, First Edition. Linear regression is not restricted to stature estimation

A procedure that specifies the optimal order in which forensic experts examine submitted documents in order to conduct a comparison and minimize the risk of bias.

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.

Material composed of carbon particles or colorants suspended in a liquid carrier. (SWGDOC E05)

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 process of planographic printing in which the image to be printed is ink receptive/water repellent, and the non-image area is ink repellent/water receptive.

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.

A test involving one odor per 0.3 meters (1 foot), 1 minute per odor.

A unique physical location of a gene (or specific sequence of DNA) within a chromosome; the plural of locus is loci (which is pronounced low-sigh).

A unique physical location on the DNA molecule.