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.
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.
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 metal or plastic cap that contains a small amount of initiating explosive, which is readily ignited by shock.
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.
A highly toned oil-based black ink. Printer's inks that set up in two to four hours are often used in the production of full circumference known tire impressions
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.
the direction of vibration to which light emerging from a polarizer has been restricted.
The direction of vibration to which light emerging from a polarizer has been restricted
The use of biological modeling (i.e., statistical modeling informed by biological data), statistical theory, computer algorithms, and/or probability distributions to infer genotypes and/or calculate likelihood ratios
Software, or software and hardware, which utilizes a probabilistic genotyping approach to infer genotypes and/or calculate likelihood ratios
A quantified measure between zero and one indicating how probable or likely it is that an event will or has occurred. In the frequentist interpretation, probability is based on the rates at which events occur. In the Bayesian interpretation, probability reflects a degree of belief. On this scale, zero indicates impossibility and one indicates absolute certainty.
Probable cause exists when the facts and circumstances known to the officer would warrant a prudent person to believe a crime had been committed and the accused had committed it or that the evidence will be found in the place to be searched.
In facial identification, a facial image or template searched against the gallery in a facial recognition (FR) system.
In facial identification, a facial image or template searched against the gallery in a facial recognition (FR) system
Specified way to carry out an activity or a process. 1) Procedures can be documented or not. 2) When a procedure is documented, the term written procedure or documented procedure is frequently used. The document that contains a procedure can be called a procedure document.
Specified way to carry out an activity or a process
set of interrelated or interacting activities which transforms inputs into outputsNOTE Adapted from ISO 9000:2005, definition 3.4.1.
Set of interrelated or interacting activities which transforms inputs into outputs
an analytical control that is derivedfrom the labware, reagents, and solvents used in various stagesof this procedure to check for interfering or contaminationproducts introduced by labware or solvents
A control to test a analytical process such as hydrolysis or oxidation of an analyte
Ordinate values that have been processed (e.g., trimmed, filtered, and/or interpolation applied).
In image and video analysis, any image that has undergone enhancement, restoration, or other op- eration.
In image and video analysis, any image that has undergone enhancement, restoration, or other operation
result of a processNOTE 1 Four generic product categories are noted in ISO 9000:2005:- services (e.g. transport) (see definition in 3.4);- software (e.g. computer program, dictionary); - hardware (e.g. engine, mechanical part);- processed materials (e.g. lubricant).Many products comprise elements belonging to different generic product categories. Whether the product is then calledservice, software, hardware or processed material depends on the dominant element.NOTE 2 Products include results of natural processes, such as growth of plants and formation of other naturalresources.NOTE 3 Adapted from ISO/IEC 17000:2004, definition 3.3.
Results of a process
In forensic audio and video analysis, a device or software or both used to mix video or audio signals or both from two or more sources. (Compare routing switcher.)
In forensic audio and video analysis, a device or software or both used to mix video or audio signals or both from two or more sources. (Compare routing switcher.)
A change of behavior of the canine followed by a positive indication that can be confirmed by the canine handler.
A change of behavior of the canine followed by a positive indication that can be confirmed by the canine handler.
See combustion products.
The mechanism through which a forensic science practitioner improves personal skills, successfully handles increasing responsibility, makes contribu- tions to the profession, and reinforces ethical behaviors.
The mechanism through which a forensic science practitioner improves personal skills, successfully handles increasing responsibility, makes contributions to the profession, and reinforces ethical behaviors
An evaluation during training; a tool to assess a canine team's ability.
An exam that tests a person's and/or an organization's ability to meet a certain level of skill in a particular activity, field of study, etc.
Laboratory, determination of laboratory testing performance by means of interlaboratory test comparisons.
Also referenced in ASTM E1732-22 Standard Terminology Relating to Forensic Science, ANSI/ASTM E1301-95 Standard Guide for Proficiency Testing by Interlaboratory Comparisons.
Evaluation of participant performance against pre-established criteria by means of interlaboratory comparison. (Source: ISO/IEC 17043:2010, 3.7 modified)
Single complete sequence of distribution of proficiency test items, and the evaluation and reporting of the results to the participants. (Source: ISO/IEC 17043:2010, 3.10)
Proficiency testing designed and operated in one or more rounds for a specified area of testing, measurement, calibration or inspection. (Source: ISO/IEC 17043:2010, 3.11)
All-encompassing plan of action aimed at accomplishing a clear objective that meets a defined need. i.e. the instruction for completing the training, certification, and documentation requirements within a detection canine discipline.
In computer forensics, a list of coded instructions causing a computer to perform a specific task or set of tasks.
In computer forensics, a list of coded instructions causing a computer to perform a specific task or set of tasks
In video analysis, a display scan pattern in which each line of the frame is scanned out sequentially.
In video analysis, a display scan pattern in which each line of the frame is scanned out sequentially
A bloodstain pattern resulting from the ejection of blood under hydraulic pressure, typically from a breach in the circulatory system.
A previously learned association that stimulates the initiation of a response. Instructions, gestures, physical guidance and modeling cues serve as prompts to the canine.
A training technique that aims to teach the canine to ignore all odors/scents except target odors/scents.
a compressed gas used to expel the contents of containers in the form of aerosols.
Any file format that is unique to a specific manufacturer or product.
Any file format that is unique to a specific manufacturer or product
Awareness of the relative body position in space at rest and during movement.