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.
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.
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)
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.
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 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 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.
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.
Application or use of measures to prevent damage, change or alteration, or deterioration.
The intentional act to prevent damage, contamination, alteration, or deterioration of anything contained within a scene.
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.
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 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 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.
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.
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
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. DISCUSSIONExamples include a digital image recorded on a flash card or a digital image downloaded from the internet.
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 cartridge case containing only a primer, without propellant or projectile.
A coating of adhesive-like material found between the tape adhesive and backing that serves as a bonding agent.
A short polynucleotide chain, usually 1830 bases long, which targets a specific region of the template DNA and allows a DNA polymerase to initiate synthesis of a complementary strand; two primers are required for amplification of a particular section of double-stranded DNA. The primers are complementary to opposite strands and are designed to bracket the region of interest for amplification. Polymerization is initiated at the 3' end of the primer and extends in a 5 to 3 manner.
A short polynucleotide chain, usually 18-30 bases long, which targets a specific region of the template DNA and allows a DNA polymerase to initiate synthesis of a complementary strand; two primers are required for amplification of a particular section of DNA. The primers are complementary to opposite strands and are designed to bracket the region of interest for amplification. Polymerization is initiated at the 3' end of the primer and extends in a 5 to 3 manner.
ignition component of a cartridge. AFTE Glossary, 6th Ed.
DISCUSSION—Commonly, a mixture of initiator, sensitizer, oxidant, fuel, and frictionator.
a metal or plastic cap that contains a small amount of initiating explosive, which is readily ignited by shock.
that portion of GSR resulting from the explosion of the primer compounds. SWGGSR
Print data includes writings, drawings, graphs, charts, photographs, images, and other material in paper or print form, including ESI that has been reproduced on paper or print media.
Data collected when the subject was in a different, previous state/condition than thecurrent state of the subject. Examples are antemortem data, when postmortem dataexists or facial images of a missing person that are compared to those of the personbeing interviewed.