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.
A change of behavior of the canine followed by a positive indication that can be confirmed by the canine handler.
A change of behavior of the canine followed by a positive indication that can be confirmed by the canine handler.
See combustion products.
the mechanism through which a forensic science practitioner improves personal skills, successfully handles increasing responsibility, makes contributions to the profession, and reinforces ethical behaviors.
An evaluation during training; a tool to assess a canine team's ability.
evaluation of participant performance against pre-established criteria by means of interlaboratory comparisons.
Also referenced in ASTM E1732-24ae1 Standard Terminology Relating to Forensic Science, ANSI/ASTM E1301-95 Standard Guide for Proficiency Testing by Interlaboratory Comparisons, ANSI/ASB Standard 153 Standard Practices for Proficiency Testing for Forensic Toxicology Laboratories and Breath Alcohol Programs.
Single complete sequence of distribution of proficiency test items, and the evaluation and reporting of the results to the participants. (Source: ISO/IEC 17043:2010, 3.10)
Proficiency testing designed and operated in one or more rounds for a specified area of testing, measurement, calibration or inspection. (Source: ISO/IEC 17043:2010, 3.11)
All-encompassing plan of action aimed at accomplishing a clear objective that meets a defined need. i.e. the instruction for completing the training, certification, and documentation requirements within a detection canine discipline.
in computer forensics, a list of coded instructions causing a computer to perform a specific task or set of tasks.
in video analysis, a display scan pattern in which each line of the frame is scanned out sequentially.
A skeletal defect often produced by high-velocity impact over a relatively small surface area, typically by projectiles from firearms, but can result from any small object impacting a bone at a high velocity.
A previously learned association that stimulates the initiation of a response. Instructions, gestures, physical guidance and modeling cues serve as prompts to the canine.
A training technique that aims to teach the canine to ignore all odors/scents except target odors/scents.
a compressed gas used to expel the contents of containers in the form of aerosols.
any file format that is unique to a specific manufacturer or product.
Awareness of the relative body position in space at rest and during movement.
A description of the specific procedures and methodologies by which a task or tasks are to be accomplished.
An established practice to be followed in performing a specified task or under specific circumstances
in computer forensics, a set of conventions governing the format and timing of message exchanges to control data movements and correct errors.
a place of origin; specifically, the area from which the constituent materials of a sedimentary rock or facies are derived.
Discussion—In the context of forensic provenance analysis, geological material is analyzed and interpreted to estimate or limit the geographic or environmental conditions of the source of this material to provide an investigative lead. For example, soil on a shovel can be examined to aid in the search for a clandestine grave, typically by comparison of observa- tions to reference data. Geographic attribution is an alternative term for provenance.
a place or origin; specifically, the area from which the constituent materials of a sedimentary rock or facies are derived, also, the rocks of which this area is composed.
Discussion—In the context of forensic provenance examination, geological material is analyzed and interpreted to estimate or limit the geographic or environmental conditions of the source of this material to provide an investigative lead. For example, soil on a shovel can be examined to aid in the search for a clandestine grave, typically by comparison of observations to reference data. "Geographic attribution" is an alternative term for provenance.
the portion of the hair closest to, and including, the root.
the portion of the hair closest to, and including, the root.
The segment of the finger or thumb closest to the palm.
The cause that directly produces the effect without the intervention of any other cause.
An artifact that may occur during analysis of fluorescently-labeled DNA fragments when signal from one dye color channel produces artificial peaks in another, usually adjacent color, at a similar position on the X axis in an electropherogram; sometimes referred to as bleed-through or matrix/ spectral calibration failure; one type of DNA testing artifact.
operator-selected value for the time designated to record a response by the detector.
Discussion—A higher value (longer time) results in a more accurate determination of the detector amplifier pulse height (better spectral resolution). A lower value results in a higher count rate but with reduced spectral resolution.
operator-selected value for the time designated to record a response by the detector. A higher value (longer time) results in a more accurate determination of the detector amplifier pulse height (better spectral resolution). A lower value results in a higher count rate but with reduced spectral resolution.
The action of the pupils constricting in response to light, it requires vision and normal neurologic control of the pupils.
The action of the pupils constricting in response to light, it requires vision and normal neurologic control of the pupils
a chromatogram obtained from the pyrolysis products of a material.
Product of decomposition through heat; a product of a chemical change caused by heating.
product of decomposition through heat; a product of chemical change caused by heating; also known as pyrolyzate or pyrolysis product.
to undergo pyrolysis; also known as pyrolyze.
to undergo pyrolysis; also known as pyrolyze.
A process in which material is decomposed, or broken down, into simpler molecular compounds by the effects of heat alone; pyrolysis often precedes combustion.
a process in which organic material is broken down into simpler molecular compounds by the effects of heat alone; pyrolysis often precedes combustion.
the thermal fragmentation of a substance in an inert atmosphere.
the temperature (set or ramped) at which the pyrolysis of the sample is performed.
the product of the pyrolysis process.
Any substance that spontaneously ignites upon exposure to atmospheric oxygen.
Any substance that spontaneously ignites upon exposure to atmospheric oxygen.
any substance that spontaneously ignites upon exposure to atmospheric oxygen.
A method of DNA sequencing which is performed by detecting the nucleotide incorporated by a DNA polymerase.
A method of DNA sequencing which is performed by detecting the nucleotide incorporated by a DNA polymerase.
a mixture of chemical substances which, on burning, produces bright or colored light, heat, smoke, or acoustic effects.
Discussion—Pyrotechnic mixtures can cause an explosion if ignited while confined.
a pellet of pyrotechnic material that contributes to the patterns and effects of an aerial firework.
Discussion—Pyrotechnic stars can come in a variety of sizes, but are generally spherical or cylindrical in shape.