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.
An employee who is accountable for the technical operations of the laboratory and who is authorized to initiate, suspend, and resume laboratory operations.
Written documentation maintained by the laboratory including laboratory policies, technical protocols and methods for specific forensic analyses (see also standard operating procedure).
A qualified second party's evaluation of reports, notes, data, and other documentation to ensure there is appropriate and sufficient support for the actions, results, conclusions, opinions, and interpretations.
Also referenced in ANSI/ASB 019 Wildlife Forensics General Standards, ANSI/ASB Technical Report 025, Crime Scene/Death Investigation - Dogs and Sensors - Terms and Definitions, ANSI/ASB 063 Implementation of 3D Technologies in Forensic Firearm and Toolmark Comparison Laboratories, ANSI/ASB 142-22 Best Practice Recommendations for the Resolution of Conflicts in Friction Ridge Examination, ANSI/ASTM E3392-24 Standard Guide for Forensic Physical Fit Examination, ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science, ANSI/ASB Standard 099 Standard for Footwear/Tire Examination Proficiency Testing Program, ANSI/ASB 168 Standard for Testimony Monitoring in Friction Ridge Examination, ANSI/ASB 143 Standard for Technical Review in Friction Ridge Examination
An individual with the knowledge/expertise to conduct the technical review to determine if theappropriate examinations have been performed, support the results/conclusions of thedevelopment and/or deployment validations, and that the reported results are consistent with therecorded data and are within the scope of testing.
Used to describe the type of forensic DNA analysis performed in the laboratory, such as SNP, STR, YSTR, or mitochondrial DNA.
The general consistence with which the animal behaves. Broad classes of temperament appear to be heritable. OutgoingBehavior of the canine characterized by seeking human interaction. StableBehavior of the canine that is consistent over time, place and environmental conditions.
The general consistence with which the animal behaves. Broad classes of temperament appear to be heritable. OutgoingBehavior of the canine characterized by seeking human interaction. StableBehavior of the canine that is consistent over time, place and environmental conditions.
The degree of sensible heat of a body as measured by a thermometer or similar instrument.
The quality of a canine to persist at a task regardless of the environmental distractions or task difficulty.
The quality of a canine to persist at a task regardless of the environmental distractions or task difficulty.
Other terms specific to firearms, such as rifle, shotgun, pistol, revolver, firearm, single action, double action, sear, and cock are described in Association of Firearm and Tool Mark Examiners, Glossary [7] and Glossary-SAAMI [1]23].
To discharge a firearm in a laboratory or controlled setting in order to obtain representative bulletsand cartridge cases for comparison or analysis, or to determine functionality of the firearm.
An impression made from a known footwear or tire used as an aid for comparison purposes.
A term intended to encompass any report containing the description of items submitted to a laboratory, as well as any results of testing and examinations that may have occurred.
statement which communicates information in a judicial setting
Note 1 to entry: Oral testimony can be accompanied by documents including written reports and other materials.
The determination, by technical means, of properties, performance or elements of materials, products, services, systems, or environments, which may involve application of established scientific principles and procedures. Testing typically applies to materials, products or processes.
See plume
The increase in length, volume, or surface area of a body with rise in temperature.
The properties of a material that characterize its rate of surface temperature rise when exposed to heat; related to the product of the material's thermal conductivity (k), its density (_), and its heat capacity (c).
Heat is used to close the non-printing area micropores on the flat die.
A skeletal defect produced by exposure to high temperature or direct contact with flame.
The branch of physics that deals with the relationship between heat and other forms of energy.
The study of the science, methodology, and practice of temperature measurement.
Plastic materials that soften and melt under exposure to heat and can reach a flowable state.
Plastic materials that are hardened into a permanent shape in the manufacturing process and are not commonly subject to softening when heated; typically form char in a fire.
A method for calculating match probabilities, first described by Balding and Nichols (1994), to allow for population structure in the population for which a frequency database is constructed. It allows match probabilities for subpopulations to be calculated from whole population allele frequencies. It avoids the need to assume Hardy-Weinberg equilibrium at the whole-population level.
An impression made on surfaces such as soil, sand, snow or mud with dimensions of length, width, and depth.
DetectionThe minimum and maximum concentration of a chemical vapor that can be detected by a canine or an instrument. BehavioralThe level of stimulation above or below which learning and/or performance is impaired.
Graphic representation of the events in a fire incident displayed in chronological order.