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.
See restoration.
in image and video analysis, any process that renders an image, using computer graphics techniques, for illustrative purposes (that is, age progression, facial reconstruction, and accident/crime scene reconstruction).
in image and video analysis, an act of moving images from one location to another.
Thin transparent plastic material that covers the item during an examination using an EDD.
in image and video analysis, any system or method used to capture, store, process, analyze, transmit, or produce an image. Discussion—Such systems include film, electronic sensors, cameras, video devices, scanners, printers, computers, and so forth.
a term that describes a scale pattern in which the scales overlap and the edges have an irregular wavy pattern; this pattern is typical of human hair.
The timing involved in delivering consequences for a response directly following the response in time. This reduces the likelihood of inadvertently reinforcing/punishing some other behavior. (See reinforcement.)
descriptive of substances of the same phase or state of matter that cannot be uniformly mixed or blended.
Make an animal immune to infection, typically by inoculation. (See vaccination.)
To make an animal immune to infection, typically by inoculation. (See vaccination.)
Any of several techniques for obtaining a precipitate between an antibody and its specific antigen by letting both antibody and antigen migrate through the gel from separate wells to form an area of precipitation (also known as ouchterlony double immunodiffusion).
Presence of objectivity
presence of objectivity
Note 1 to entry: Objectivity means that conflicts of interest do not exist, or are resolved so as not to adversely influence subsequent activities of the laboratory (3.6).
Note 2 to entry: Other terms that are useful in conveying the element of impartiality include freedom from conflict of interests, freedom from bias, lack of prejudice, neutrality, fairness, open-mindedness, even-handedness, detachment, balance. [SOURCE: ISO/IEC 170211:2015, 3.2, modified. The words the certification body have been replaced by the laboratory in Note 1 to entry, and the word independence has been deleted from the list in Note 2 to entry.]
A friction ridge image containing friction ridge detail produced on a surface by pressure.
Image formed by pressure.
Manner in which the paper is embossed or shredded.
A phenomenon by which an animal during a formative stage of life forms a lasting attachment to, and preference for, some object or activity through exposure to the same independent of consequences. Operational usage: A method of initial odor/scent discrimination training.
any combination of items or components that are neither originally designed nor produced to be used in conjunction with each other and, when placed together, constitute a mechanism that has the capability of exploding and causing personal injuries and property damage.
A database of reference material or sequences assembled internally by a forensic laboratory.
Reinforcement delivered despite the appropriateness of any response on the part of the subject.
chemical compound, metal, or mixture capable of producing intense heat.
a device or mechanism used to initiate an incendiary fire.
A fire that is intentionally ignited in an area or under circumstances where and when there should not be a fire.
A management system designed to enable effective and efficient domestic incident management by integrating a combination of facilities, equipment, personnel, procedures and communications operating within a common organizational structure.
Location at which a fatal injury or fatal sequence of events was initiated. This may or may not be the death scene.
A soil level in an excavation or grave that does not contain evidence or data relevant to the scene under investigation. It does not mean that it is culturally or archaeologically sterile (e. g. historic or prehistoric artifacts or features may be present but are not related to the event under investigation).
A friction ridge not fully developed that may appear shorter and thinner in appearancethan fully developed friction ridges.
The InterNational Committee for Information Technology Standards
A type location check in which a scent match is indicated by the canine thereby including an individual as the scent contributor.
A conclusion for which an individual is a potential contributor of DNA (i.e., cannot be excluded) obtained from an evidentiary sample based on the comparison of DNA data; a statement of inclusion does not confirm that an individual is a source of the DNA.
spectral artifacts that result from inelastic scattering of the tube target characteristic X-rays by the sample.
Discussion—Because energy is lost in inelastic scattering, incoherent scatter peaks occur at a lower energy than the tube target characteristic X-rays.
A concept in evolutionary theory in which genetic isolation leads to the divergence of descendant species from their common ancestors. Incomplete lineage sorting is reflected in the retention of shared ancestral genetic or morphological characteristics between closely related species.
the result of a comparison between two hair samples in which similarities and differences were observed in the characteristics of the provided standard and the questioned hair to the extent that the known source of the standard could not be included or excluded as a possible source of the questioned hair.
A determination that no conclusion (i.e., inclusion or exclusion) can be drawn from the comparison of reference data to evidentiary data. This could also result from statistical analyses that fail to provide sufficient support for an inclusion or exclusion.
The conclusion that the observed data does not provide more support for one proposition over the other.
Results that do not meet criteria for reporting, or were unsuitable due to analytical interferences or condition of the sample
The conclusion that the observed data provide more support for the proposition that the impressions originated from different sources rather than the same source; however, there is insufficient support for a Source Exclusion.
The conclusion that the observed data provide more support for the proposition that the impressions originated from the same source rather than different sources; however, there is insufficient support for a Source Identification.
in fire debris, used as a generic term for substituted forms of indan, a compound which consists of a benzene ring fused to a cyclopentane ring.
Discussion—In the plural form, sometimes used in fire debris analysis to refer to the class of compounds based on indan; they can be found in gasoline and, to an extent, in other petroleum products.
Latent or visible impressions and/or embossments in paper or other media. This also includes paper fiber disturbances which do not optically appear as impressions.
Latent or visible impressions in paper or other media.
Scientific usage: Statistical studies assume a property called independence - a situation where the data collected are not related to each other because they come from a random sample from the population examined; independence is often assumed but seldom tested. Good statistical testing tests for independence when its presence is unclear. Operational usage: The canine's capability to perform without assistance or being influenced by the canine handler.
Scientific usage: Statistical studies assume a property called independence - a situation where the data collected are not related to each other because they come from a random sample from the population examined; independence is often assumed but seldom tested. Good statistical testing tests for independence when its presence is unclear. Operational usage: The canine's capability to perform without assistance or being influenced by the canine handler.
In the simplest experiment this is the item that you vary or that varies as a function of the way the experiment is designed.
The process of obtaining a second analysis from a forensic dental age assessment practitioner, blinded to the results of the first practitioner's assessment.
The canine's response to the odor/scent in the manner in which it has been trained, independently and without distraction. (See alert, final response.)
the attribute(s) that establish(es) a single source.
Discussion—Other terms used include random accidental characteristics, randomly acquired characteristics, and distinguishing characteristics.