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.
flange-headed cartridge containing the priming mixture inside the rim cavity.
The degree of peril; the possible harm that might occur that is represented by the statistical probability or quantitative estimate of the frequency or severity of injury or loss.
An uncertain event or condition that, if it occurs, has a negative effect on a softwares reliability and performance.
A systematic process for deciding the risk level associated with a particular software or module.
Experiments performed to measure the capability of a procedure to remain unaffected by small but deliberate variations in method parameters and provide an indication of reliability during normal usage.
long, thin crystals with squared off ends.
Region of interest.
in facial identification, an intrinsic rotation of the head about a horizontal front-to-back (sagittal) axis measured in degrees. Discussion—Frontal poses have a roll angle of 0. Positive angles represent faces tilted toward their right shoulder (counter-clockwise rotation around the axis). A roll angle of 0 denotes that the left and right eye centers have identical vertical coordinates. The roll axis is typically defined as the Z-axis (positive forward).
A fingerprint image collected by rolling the finger across a livescan platen or paperfingerprint card from nail to nail. Rolls may be from livescan devices or scanned frompaper fingerprint cards.
A commercial product, which is a seven-mil Estar film base material designed to wet rollers andpick up loose particles on all types of roller transport photo-processing machines used along withfingerprint powder to produce known impressions of footwear and tires.
The linear distance traveled by a tire in one revolution under load.
See flameover.
the structure that anchors a hair to a follicle and from which cells divide and produce the hair shaft.
Discussion—The portion of follicular tissue surrounding a root structure is the sheath.
a compact and flexible, torsionally balanced structure produced from strands which are laid, plaited, or braided together to produce a product which serves to transmit a tensile force between two points.
Discussion—Generally greater than 3⁄16 in. diameter; a rope is made up of three or more strands.
Canine training conducted with regularity that maintains the canine's operational capabilities.
Canine training conducted with regularity that maintains the canine's operational capabilities.
in forensic audio and video analysis, device or software or both used to direct the path of one or more signals into one or more devices. (Compare production switcher.)
set of samples contemporaneously analyzed (unbroken sequence) as part of an experiment or calibration
A document providing comprehensive information about a substance or mixture for using in workplace chemical management as adopted by the Globally Harmonized System of Classification and Labeling of Chemicals (GHS). Note: Previously known as a Material Safety Data Sheet (MSDS).
A document providing comprehensive information about a substance or mixture for using in workplace chemical management as adopted by the Globally Harmonized System of Classification and Labeling of Chemicals (GHS). NOTE Previously known as a material safety data sheet (MSDS).
A water-proof, coated, thread-wrapped cord with a black powder core designed to be used to initiate a non-electric blasting cap.
Discussion—Safety fuse is larger in diameter than hobby or pyrotechnic fuse, has higher quality construction, and has better reproducibility in timing (distance burned per second).
An action by the handler, canine or canine team that if done in operational environment, could place the canine team in jeopardy.
Subset of a population made up of one or more sampling units.
a representative portion of the specimen selected and prepared for analysis that is expected to exhibit all of the elemental characteristics of the parent specimen.
Obtain the values of a function for regularly or irregularly spaced distinct values fromits domain. From: ISO 2382-2:1976.
a sample for which the identity of the donor is established and which is used for comparison purposes.
a sample of known hairs that is insufficient in quality or quantity to reflect a representative range of characteristics or traits.
a collection of hairs from a specific somatic region that reflects the range of characteristics in a person's hair in that area.
process of drawing or constituting a sample.
one of the individual parts into which a population is divided.
A method of DNA sequencing for determining the order of bases in a DNA molecule based on the selective incorporation of chain-terminating dideoxynucleotides by DNA polymerase during in vitro DNA replication.
A method of DNA sequencing for determining the order of bases in a DNA molecule based on the selective incorporation of chain-terminating dideoxynucleotides by DNA polymerase during in vitro DNA replication. See sequencing below.
Subject Acquisition Profile. With the exception of mobile device SAP levels, they are aseries of sets of progressively more stringent parameters and requirements relevant toface acquisition. Subject Acquisition profiles for iris are denoted as Iris acquisitionprofiles (IAP), and those for fingerprints are denoted as Fingerprint acquisitionprofiles (FAP). The term SAP had been used exclusively for face acquisition in earlierversions of the standard. [2015a>] In the Mobile ID Best Practices RecommendationsVersion 1, face, finger and iris application profiles were all referred to as SAP. Theyare referred to separately in this standard. This was changed in Mobile ID Best Practices Recommendations Version 2 to be consistent with this standard.
When a reinforcer loses its effectiveness as a result of being overused.
overlapping, plate-like structures composed of keratin that form the cuticle.
a type of electron microscope in which a focused electron beam is scanned in a raster on a solid sample surface; the term can also include the analytical technique of energy dispersive X-ray spectroscopy.
The number of pixels per unit distance at which an image is captured (ppmm or ppi).
Healed fibrous tissue resulting from an injury to the skin.
subtle curved line on a fracture surface caused by interaction of a propagating crack and a liquid or a reactive environment.
The general physical location of a fire or explosion incident (geographic area, structure or portion of a structure, vehicle, boat, piece of equipment, etc.) designated as important to the investigation because it may contain physical damage or debris, evidence, victims, or incident-related hazards.
A place, an object, a person, or an animal that is subject to and/or requires forensic examination. NOTE A crime scene is a common description of a scene where a presumed crime has been committed. The scene can be a person or an animal. (ISO 21043-1:2018[E])
NOTE In a situation that involves a potential criminal act definitions in section 3.7 through 3.9 would be preceded by “crime” (e.g., crime scene investigator).
A place, an object, a person, or an animal that is subject to and/or requires forensic examination
NOTE In a situation that involves a potential criminal act definitions in section 3.1 through 3.5 would be preceded by “crime” (e.g., crime scene investigator).
An examination of a scene to locate, document, process, collect, and preserve items of potential evidentiary value.
NOTE In a situation that involves a potential criminal act definitions in section 3.7 through 3.9 would be preceded by “crime” (e.g., crime scene investigator).
An examination of a scene to locate, document, process, collect, and preserve items of potential evidentiary value.
NOTE In a situation that involves a potential criminal act definitions in section 3.1 through 3.5 would be preceded by “crime” (e.g., crime scene investigator).
An individual, however named, who is responsible for performing elements of scene investigation.
NOTE In a situation that involves a potential criminal act definitions in section 3.7 through 3.9 would be preceded by “crime” (e.g., crime scene investigator).