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.
Biological sample recovered from a crime scene or collected from persons or objects associated with a crime.
The application of scientific principles and techniques to matters of criminal justice especially as relating to the collection, examination, and analysis of physical evidence.
An individual who (1) applies scientific or technical practices to the recognition, collection, analysis, or interpretation of evidence at issue in criminal, civil, or administrative investigations and proceedings, and (2) issues test results, provides reports, or provides interpretations, conclusions, or opinions through testimony with respect to such evidence.
an individual who (1) applies scientific or technical practices to the recognition, collection, analysis, or interpretation of evidence for criminal and civil law or regulatory issues; and (2) issues test results, provides reports, or provides interpretations, conclusions, or opinions through testimony with respect to such evidence.
an individual who (1) applies scientific or technical practices to the recognition, collection, analysis, or interpretation of evidence for criminal and civil law or regulatory issues; and (2) issues test results, provides interpretations, or opinions through reports or testimony with respect to such evidence.
An organization or individual that provides forensic science services.
Also referenced in ANSI/ASB 017 Standard Practices for Measurement Traceability in Forensic Toxicology, ASTM E1732-24ae1 Standard Terminology Relating to Forensic Science, ANSI/ASTM E2917-24a Standard Practice for Forensic Science Practitioner Training, Continuing Education, and Professional Development Programs, ANSI/ASTM E3255-21 Standard Practice for Quality Assurance of Forensic Science Service Providers Performing Forensic Chemical Analysis, ANSI/ASB 142-22 Best Practice Recommendations for the Resolution of Conflicts in Friction Ridge Examination, ANSI/ASB Standard 157-23 Required Components for a Proficiency Testing Program in Bloodstain Pattern Analysis
The detection, characterization, identification, and/or typing of body tissues and fluids, either in native form or as stains or residues left at a crime scene using physical methods (e.g. normal and enhanced lighting), biochemical assays, reactions and/or microscopy.
The detection, characterization, identification, and/or typing of body tissues and fluids, either in native form or as stains or residues left at a crime scene using physical methods (e.g. normal and enhanced lighting), biochemical assays, reactions and/or microscopy.
An organization or individual that provides forensic services.
Also referenced in ANSI/ASB 145 Standard for Consultation During Friction Ridge Examination, ANSI/ASB Best Practice Recommendation 144 Best Practice Recommendations for the Verification Component in Friction Ridge Examination, ANSI/ASB Best Practice Recommendation 165 Best Practice Recommendation for Analysis of Friction Ridge Impressions, ANSI/ASB Best Practice Recommendation 166 Best Practice Recommendation for Comparison and Evaluation of Friction Ridge Impressions, ANSI/ASB 014 Standard for Friction Ridge Examination Training Program, ANSI/ASB Standard 015 Standard for Examining Friction Ridge Impressions, ANSI/ASB 168 Standard for Testimony Monitoring in Friction Ridge Examination, ANSI/ASB 143 Standard for Technical Review in Friction Ridge Examination, ANSI/ASB 167 Standard for Reporting Results from Friction Ridge Examinations.
Activities included in the collection, examination, and analysis of items and reporting of observations and opinions for matters of criminal justice, or for regulatory, or legal proceedings.
See video analysis.
in computer forensics, a verifiable procedure for sanitizing a defined area of digital media by overwriting each byte with a known value.
the structure by which data are organized on a device.
Discussion—A format can refer to a physical medium, a type of signal, a file format, encoding parameters, or combinations thereof.
to prepare a hard disk or a removable data storage device to enable data storage using a specified filesystem or data structure.
in audio, image, and video analysis, the transfer of audio or video information, or both, from one format to another.
the means and methods for characterizing fractured specimens or compounds.
high-speed missiles that are the result of an explosion and may be part of the explosive casing; container; earth; building material; target area; or other items affected by the explosion.
in video analysis, the lines of spatial information of a video signal. Discussion—For interlaced video, a frame consists of two fields, one of odd lines and one of even lines, displayed in sequence. For progressive scan (non-interlaced) video, the frame is written through successive lines that start at the top left of the picture and finish at the bottom right.
The internal bony structures that give the shape and proportion to the canine.
The internal bony structures that give the shape and proportion to the canine.
The plane determined by the lowest point of the left eye socket and the tragions of theears.
See unallocated space.
The rate at which an event occurs.
A human scent pathway that has been present for a short period of time. A trail that is under 24 hours old.
The examination of impressions from fingers, palms or soles, for identification purposes.
The combination of ridge flow, ridge characteristics, and ridge structure of friction ridge skin, as reproduced and observed in an impression. The observed data used to compare and interpret similarity or dissimilarity between impressions.
The combination of ridge flow, ridge characteristics, and ridge structure of friction ridge skin, as reproduced and observed in an impression. The observed data used to compare and interpret similarity or dissimilarity between impressions.
The combination of ridge flow, ridge characteristics, and ridge structure of friction ridge skin, as reproduced and observed in an impression. The observed data used to compare and interpret similarity or dissimilarity between impressions.
The combination of ridge flow, ridge characteristics, and ridge structure of friction ridge skin, as reproduced and observed in an impression. The observed data used to compare and interpret similarity or dissimilarity between impressions.
An image of an impression from the palmar surfaces of the hands or fingers, or from theplantar (sole) surfaces of the feet or toes.
The volar skin surface of the surfaces of the hands and fingers, and the plantar surfaces ofthe feet and toes.
provides sharp corners against which the particles of sensitizer and initiator are forced by the movement of the primer cup or case rim under the firing pin blow.
in facial identification, a facial image captured from directly in front of the subject with the focal plane approximately parallel to the plane of the subject's face.
a material that will maintain combustion under specified environmental conditions.
any substance capable of reacting with oxygen and oxygen carriers (oxidizers) with the evolution of heat.
chemical compound or mixture of compounds added to a fuel for various purposes.
Natural gas, manufactured gas, LP-Gas, and similar gases commonly used for commercial or residential purposes such as heating, cooling, or cooking.
Natural gas, manufactured gas, LP-Gas, and similar gases commonly used for commercial or residential purposes such as heating, cooling, or cooking.
The total quantity of combustible contents of a building, space, or fire area, including interior finish and trim, expressed in heat units or the equivalent weight in wood.
A fire in which the heat release rate and growth rate are controlled by the characteristics of the fuel, such as quantity and geometry, and in which adequate air for combustion is available.
indicating a ratio of oxygen-to-fuel that provides less oxygen than needed for optimum combustion of the fuel.
A full finger view is a rolled or plain image of a full-length finger showing all segments.An entire joint image includes four full finger view images: one rolled; left, center, andright plain.
Condition in a compartment fire in which the entire volume is involved in combustion of varying intensities.
Operation of a mass spectrometer in which abundances of ions for entire mass spectrum arerecorded over a defined mass range.