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.
Checking to confirm that the natural (or usual) inputs yield the expected output.
Mode of dynamic headspace concentration extraction using a gas under positive pressure to force the headspace through the adsorbent media.
Upon presentation of the reward article, the canine takes the article without hesitation, and maintains a firm grip.
An analytical procedure to determine the amount of amplicon obtained after DNA amplification.
After death.
The appearance of an opaque band near the root/proximal end of a hair potentially observed in anagen or catagen hairs that have been removed from a decomposing body; the possibility of other conditions causing the same or similar characteristics cannot be eliminated (Koch, S.L., Michaud, A.L., and Mikell, C.E., Taphonomy of Haira Study of Postmortem Root Banding, Journal of Forensic Sciences, Vol 58, No. s1, 2013, pp. S52S59).
the appearance of an opaque band near the root/proximal end of a hair potentially observed in anagen or catagen hairs that have been removed from a decomposing body. The possibility of other conditions causing the same or similar characteristics cannot be eliminated.
The analysis of specimens from decedents to determine the presence of drugs or other chemicals for the purpose of medico-legal death investigation.
The position in which the body is held.
The position in which the body is held.
One pound-force, 1 lbf, is defined as the weight of a one avoirdupois pound, 1 lb, mass at standard gravity.1 lbf (pound-force) 4.448 N (newtons)1 N (newton) 0.2248 lbf (pound-force)NOTE The SI unit of force is the newton, symbol N. In the U.S., it is customary to specify the trigger pull force in pound-force, symbol lbf.NOTE Pound-force lbf is sometimes referred to as pound lb where the context refers to force rather than mass.
A disparaged term for an irregular pattern that may be observed at a fire scene. This kind of pattern should not be identified as resulting from ignitable liquids on the basis of observation of the visual appearance alone.
A property of a process, such as fire, which describes the amount of energy that is emitted, transferred, or received per unit time and is measured in joules per second (J/s) or watts (W).
Pixels per inch.
Pixels per millimeter.
Physically removing the canine, after he has shown a response, from the area or item without causing any physical discomfort to the canine, while verbally praising the canine.
A sample target scent that is presented to the canine prior to deployment. The canine's objective is to match the scent article to the target scent. This is commonly used in tracking/trailing/location checks and/or scent discrimination line ups.
A representative target scent that is presented to the canine prior to deployment. The canine's objective is to associate the scent article to the target scent. This is commonly used in tracking/trailing/location checks and/or scent discrimination line ups.
A representative target scent that is presented to the canine prior to deployment. The canine's objective is to associate the scent article to the target scent. This is commonly used in tracking/trailing/location checks and/or scent discrimination line ups.
A representative target scent that is presented to the canine prior to deployment. The canine's objective is to associate the scent article to the target scent. This is commonly used in tracking/trailing/location checks and/or scent discrimination line ups.
A type of canine that smells a sample target odor pad (scent article) prior to deployment. The canine's objective is to match the pre-scented pad to the target scent. This is commonly used in tracking/trailing and/or scent discrimination line ups.
The measure of the closeness of agreement between a series of measurements obtained from multiple samplings of the same homogenous sample. It is expressed numerically as the coefficient of variation (%CV)
Studies performed to evaluate the variation in likelihood ratios calculated from repeated software analyses of the same input data using the same set of conditions/parameters. Probabilistic genotyping systems inherently do not produce the same exact numbers in repeated analysis. These studies should demonstrate the range of values that can be expected from multiple analyses of the same data
Laboratory test results that are pending confirmatory analysis
A flame for which the fuel and oxidizer are mixed prior to combustion, as in a laboratory Bunsen burner or a gas cooking range; propagation of the flame is governed by the interaction between flow rate, transport processes, and chemical reaction.
The interval in human development that occurs prior to birth.
Application or use of measures to prevent damage, change or alteration, or deterioration.
In computer forensics, a process undertaken to maintain the integrity of potential digital evidence.
In computer forensics, a process undertaken to maintain the integrity of potential digital evidence
The intentional act to prevent damage, contamination, alteration, or deterioration of anything contained within a scene.
An outsole made in the compression mold.
An adhesive that consists of a polymeric base, usually with appropriate plasticizers and tackifiers. It can form an adhesive bond with no physical or chemical change and with the application of only slight pressure.
A combination of a pressure sensitive adhesive with a continuous flexible backing (cloth, paper, metal, or plastic) or with a backing and release liner. DiscussionUse of the word 'tape' in this guide refers to PSA tapes and their components.
A viscoelastic material which, in solvent-free form, remains tacky and will adhere instantaneously to most solid surfaces with the application of very slight pressure
Viscoelastic material which, in solvent-free form, remains tacky and will adhere instantaneously to most solid surfaces with the application of very slight pressure
A combination of a pressure sensitive adhesive with a continuous flexible backing (for example, cloth, paper, metal, or plastic) or with a backing and release liner
A combination of a pressure sensitive adhesive with a continuous flexible backing (for example, cloth, paper, metal, or plastic) or with a backing and release liner
A screening test that indicates the possible presence of a material of interest. A positive presumptive test result does not constitute the identification of that material. A negative presumptive test indicates that the material of interest was not detected; it is not confirmation of its absence. Presumptive tests are sensitive but not specific and can lead to false positive results.
A screening test which may be positive in the presence of a biological material of interest. Some presumptive tests are sensitive but not specific. A positive result indicates that further testing could be informative.
The innate impulse of a canine to grasp prey. This drive can be delineated as 'instinctive' prey drive (prey consists of natural targets like birds, rodents, etc.) and 'imprinted' prey drive (prey consists of learned targets such as toys, balls, sticks, etc.). A canine's overall prey drive is a ratio of instinctive and imprinted prey drives.
Small commercially-made spherical particles of a material. DISCUSSION: Ammonium nitrate is commonly manufactured in prill form.
An enclosure used for long-term housing of the adult canine or puppy.
A high explosive that is extremely sensitive to initiation with a spark; weak flame; static electricity; or a mild shock; which is used to initiate secondary explosives.
The first instance in which an image is recorded onto any media that is a separate, identifiable object. DISCUSSIONExamples include a digital image recorded on a flash card or a digital image downloaded from the internet.
First instance in which an image is recorded onto any media that is a separate, identifiable object. DiscussionExamples include a digital image recorded on a flash card or a digital image downloaded from the Internet.
The first instance in which an image is recorded onto any media that is a separate, identifiable object
An impression on a document(s) or other substrate(s) beneath the originating document caused by the act of writing or other dynamic actions.
The delivery of a naturally occurring stimulus that requires no previous experience or learning to be reinforcing. It satisfies some biological need (i.e., food, water, air, social interaction).
A coating of adhesive-like material found between the tape adhesive and backing that serves as a bonding agent.
A cartridge case containing only a primer, without propellant or projectile.