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.
Ordinate values within a dataset that received an erroneous signal during the measurement and nolonger represent the real surface. These often appear as spikes in the dataset. Detection methodsinclude local slope and neighboring height thresholding.
A term used to describe a specific pattern or arrangement of design elements on an outsoletypically associated with a manufacturer and having a name and/or style number.
Any current in excess of the rated current of equipment or the ampacity of a conductor; it may result from an overload (see short circuit or ground fault).
A fire fighting term involving the process of final extinguishment after the main body of the fire has been knocked down. All traces of fire must be extinguished at this time.
Operation of equipment in excess of normal, full-load rating or of a conductor in excess of rated ampacity that, where it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.
oval-shaped, heavily-pigmented inclusions usually found in the hair cortex.
A substance, not necessarily containing oxygen, that causes oxidation.
the combination of one compound or element with another that involves the loss of electrons from its atomic structure.
Discussion—Oxidation and reduction always occur simultaneously (redox reactions), and the substance that gains electrons is termed the oxidizing agent.
a material that releases oxygen, or that reacts readily with fuels, and enables the initiation or increased intensity of a fire or explosion.
compounds generally containing oxygen that react vigorously with fuel compounds (reductants) thereby increasing the energy of the deflagration of the primer.
Insufficiency of oxygen to support combustion. (See also Ventilation-Controlled Fire)
a pigmented coating.
commonly known as a pigmented coating (see coating).
The roof of the mouth separating the oral cavity from the nasal cavity. Canines have a bony hard palate and a soft tissue extension called the soft palate.
The roof of the mouth separating the oral cavity from the nasal cavity. Canines have a bony hard palate and a soft tissue extension called the soft palate.
A friction ridge image from the palm (side and underside) of the hand. A full palm printincludes the area from the wrist to the tips of the fingers.
Acronym for Palm print Acquisition Profile. It is a series of sets of progressively morestringent parameters and requirements relevant to palm print acquisition.
a type of device manufactured for the capture of account data from magnetically encoded cards that operates in-line with the original ATM, gas pump, or other card reading device.
in computer forensics, a logical portion of a media that functions as though it were physically separate from other logical portions of the media.
see passive headspace concentration.
A trained final response given by the canine that requires an inactive behavior such as sitting, staring or lying down. These types of behaviors are typically trained so as not to disturb the environment and/or forensic evidence.
A trained final response given by the canine that requires an inactive behavior such as sitting, staring or lying down. These types of behaviors are typically trained so as not to disturb the environment and/or forensic evidence.
A trained final response given by the canine that requires an inactive behavior such as sitting, staring or lying down. These types of behaviors are typically trained so as not to disturb the environment and/or forensic evidence.
A trained final response given by the canine that requires an inactive behavior such as sitting, staring or lying down. These types of behaviors are typically trained so as not to disturb the environment and/or forensic evidence. (See passive response, response.)
Any component of a building or structure that provides protection from fire or smoke without any type of system activation or movement. [3, 2018]
an extraction technique in which a portion of the headspace vapors in the sample container is concentrated onto an adsorbent medium.
A type of response that the canine displays/indicates in a manner that does not disturb the environment (i.e., sit, stand, lie quietly, or focus/stare after the detector canine has detected a trained odor). (See passive alert.)
in computer forensics, the process of locating and identifying a series of characters used to restrict access to data or a system.
Skeletal and/or dental abnormality resulting from disease processes.
A physician who has graduated from medical school and is either in a pathology residency or a forensic pathology fellowship program.
Pulse Code Modulation. Refers to a method of representing an analog audio waveform with a series of quantizeddigital sample values.
A version of the WAV file format which saves the data as uncompressed linear PCM samples with a standard RIFFheader.
An additive for optimizing the specificity and yield of a PCR reaction.
Any substance that interferes with or prevents the synthesis of DNA during the amplification process.
Any substance that interferes with or prevents the synthesis of DNA during the amplification process.
A family tree or a structure depicting relatedness and position of known and unknownpersons.
An independent evaluation of a scientific, professional, or academic manuscript or publication by a qualified second party to evaluate the claims, methods, interpretations, and conclusions.
Also referenced in ANSI/ASB Technical Report 025, Crime Scene/Death Investigation - Dogs and Sensors - Terms and Definitions, ASTM E2916-13 Standard Terminology for Digital and Multimedia Evidence Examination.
a hole in a disc powder or one or more holes running through the length of a cylinder powder created during the manufacturing process in extruded powders.
A quality assurance measure to assess the functionality of the probabilistic genotyping software following a minor change such as reformatting of output reports. This would typically involve functional testing of the software verifying it is performing tasks as expected and comparing results to previously validated versions of the software using the same data or sample set where possible
A quality assurance measure to assess the functionality of laboratory instruments and equipment that affect the accuracy or validity of forensic sample analysis.
A quality assurance measure to assess the functionality of laboratory instruments, reagents and equipment that affect the accuracy and/or validity of forensic sample analysis.
The ongoing process of evaluating a forensic service providers ability to perform work. Examples include quality control measures, observation, case review, retesting, blind testing, testimony monitoring, intra- or interlaboratory comparisons, and proficiency testing.