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.
item(s) that could link a person, place, or thing with another person, place, or thing.
The result of a comparison between two hair samples in which the characteristics of the questioned hair are present in the known sample without any exclusionary differences, and therefore the donor of the known hair sample can be included as a possible source of the questioned hair.
Discussion—A microscopical association of hair cannot identify the definitive source of a questioned hair to the exclusion of all others, and the number of individuals who could be included as a possible donor of a specific hair is unknown and cannot be reliably estimated.
the result of a comparison between two hair samples in which the characteristics of the questioned hair are present in the known hair sample without any exclusionary differences and, therefore, the donor of the known sample can be included as a possible source of the questioned hair.
Discussion—A microscopical association of hair cannot identify the definitive source of a questioned hair to the exclusion of all others and the number of individuals who could be included as a possible donor of a specific hair is unknown and cannot be reliably estimated.
A pathway laid by a human subject whose scent is associated with the scent on the article presented to the canine.
A pathway laid by a human subject whose scent is associated with the scent on the article presented to the canine.
A pathway laid by a human subject whose scent is associated with the scent on the article presented to the canine.
in facial identification, a submission of a single set of biometric samples to a biometric system for identification or verification. (Compare biometric search.)
a method of spectrophotometric analysis based on the reflection of energy at the interface of two media which have different refractive indices and are in intimate contact with each other.
An assertion, based on a decision following review, that specified requirements have been fulfilled.
the processing and filtering of audio recordings to improve the signal quality and intelligibility of the signals of interest, such as speech, by attenuating noise or otherwise increasing the signal-to-noise ratio.
A systematic and documented inspection of one's own organization used to assess documentation, activities, and objective evidence by comparing against established criteria and determining the extent those criteria are met.
The action of listening to sounds from the heart, lungs, or other organs, typically with a stethoscope, as a part of medical evaluation.
The action of listening to sounds from the heart, lungs, or other organs, typically with a stethoscope, as a part of medical evaluation.
Process of assessing a level of confidence in identify or identification.
Initiation of combustion by heat but without a spark or flame.
The lowest temperature at which a combustible material ignites in air without a spark or flame.
The Automated Biometric Identification System (IDENT) is the central Department of Homeland Security (DHS)-wide system for storage and processing of biometric and associated biographic information for national security; law enforcement; immigration and border management; intelligence; background investigations for national security positions and certain positions of public trust. The IDENT database is considered another one of the largest biometric databases.
Biometric computer system that allows forensic examiners to encode, digitize, and search recovered fingerprint impressions against fingerprint record databases for identification purposes.
The process or technology which accepts speech as input and determines what wasspoken.
A stimulus or training method that animal will work to avoid or terminate.
Observable response(s) indicating desire to avoid a stimulus (may be motivated by fear but can occur without fear; e.g., learned or inherent dislike of a noxious or irritating stimulus)
Training procedure relying on the use of unpleasant stimuli. For example, when a canine receives a correction on the leash as it is lunging for food on the floor in the work environment. Canine learns that lunging for food is an unpleasant experience.
A stimulus that an animal will work to terminate or avoid.
Observable response(s) that is indicative of a desire to refrain from contact or engagement with a stimulus.
The process in which an animal responds to a signal to avoid unpleasant consequences. (See aversive stimulus.) Example: A canine sits on command to avoid a correction
Intentionally pairing a behavior with displeasure to develop a desired outcome. (See avoidance learning.)
The process in which an animal responds to a signal to avoid unpleasant consequences (aversive stimulus). (See avoidance conditioning.)
The pairing of displeasure with a negative behavior in order to extinct the behavior. (See 3.31 avoidance learning.)
A conflict resulting from being repelled by two undesirable goals or stimuli when there are strong pressures to choose one or the other. Often when the conflict is intense the canine will refuse to choose between the alternatives.
a thin flexible material to which adhesive is applied.
A deflagration resulting from the sudden introduction of air into a confined space containing oxygen-deficient products of incomplete combustion.
apparent absorption caused by anything other than the substance for which the analysis is being made.
the signal produced by the entire analytical system apart from the material of interest.
X-rays resulting from scattered Bremsstrahlung and coherently and incoherently scattered tube target peaks.
X-rays resulting from scattered Bremsstrahlung and coherently and incoherently scattered tube target peaks.
a recovered sample from a source believed not to have been exposed to pGSR.
Discussion—Background samples can be used to establish a threshold value.
in facial identification, a light source placed behind a subject in a controlled capture that reduces background shadows.
a characteristic of a subject or an object that is illuminated from behind.
a technique that uses high energy electrons that originate from the primary electron beam of the SEM and are elastically reflected by the specimen to create an image of the sample. The probability of backscattering is proportional to atomic number.
a layer applied to the top side of the backing. Its purpose is to coat and fill a porous surfaced backing with a material that is inert to the adhesive formulation to be used.
A canine that is trained, certified, and/or works with more than one certified canine handler.
a class of smokeless powders produced by a process where the final grain morphologies are spherical, flattened-ball, or flake.
one or more colored areas (circular to elongated shape) on a TLC plate produced by the separation of the dye components for a particular combination of solvent and stationary phase. Bands are created as the solvent (mobile phase) moves past and reacts with the solute, migrating from the origin.
Discussion—“Spot” may also be used to describe this area.
Items used to conceal a target source in order to test the canine to perform the bark indication.
a filter used in fluorescence microscopy that absorbs excitation energy that has been reflected by the sample, selectively transmitting only wavelengths of light greater than the cut-off wavelength, or within a specific wavelength range.
the main high explosive charge.