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.
The range of concentrations between the lower and upper flammable limits.
A fire that spreads by means of a flame front rapidly through a diffuse fuel, such as dust, gas, or the vapors of an ignitible liquid, without the production of damaging pressure.
the lowest temperature corrected to a pressure of 101.3 kPa (760 mm Hg) at which application of an ignition source causes the vapors of a specimen of the sample to ignite under specified conditions of the test
The lowest temperature of a liquid, as determined by specific laboratory tests, at which the liquid gives off vapors at a sufficient rate to support a momentary flame across its surface.
A mixture of strong inorganic oxidizer; such as perchlorate or chlorate salts; and finely divided metal fuel; such as aluminum or magnesium powders; also known as photoflash powder. DISCUSSIOSulfur powder; often used as a fuel/tinder; and carbonaceous filler materials can also be present in flash powder.
Excess material from the molding process.
A transition phase in the development of a compartment fire in which surfaces exposed to thermal radiation reach ignition temperature more or less simultaneously and, given sufficient availability of oxygen, fire spreads rapidly throughout the space, resulting in full room involvement or total involvement of the compartment or enclosed space.
A fingerprint image resulting from the touching of a single finger to a livescan platen orpaper fingerprint card without any rolling motion. Also known as a single-finger plainimpression.
Smooth paper backing masking tape (saturated paper tape).
A bloodstain resulting from the movement of a volume of blood on a surface due to gravity or movement of the target.
the emission of light by a fiber that has absorbed light or other electromagnetic radiation of shorter wavelength (higher energy).
The emission of light by a fiber that has absorbed light or other electromagnetic radiation of shorter wavelength (higher energy)
a microscope equipped with a high energy light source (usually a xenon or mercury vapor lamp) and a set of excitation and barrier filters along with a dichromatic mirror, used to induce and observe fluorescence in fibers and other particles or materials.
A microscope equipped with a high energy light source (usually a xenon or mercury vapor lamp) and a set of excitation and barrier filters, used to induce and observe fluorescence in fibers and other particles or materials
The distance from the optical center of a lens to its point of focus at the sensor or image plane when focused at infinity.
The distance from the optical center of a lens to its point of focus at the sensor or image plane when focused at infinity.
The distance from the optical center of a lens to its point of focus at the sensor or image plane when focused at infinity
Surface topography measurement method whereby the sharpness of the surface image (or anotherproperty of the reflected light at optimum focus) in an optical microscope is used to determine thesurface height at each position along the surface.
Tissue from a hair follicle that is still attached to the root end of a hair which has been forcibly removed.
The subconscious impulse to work to obtain food.
The innate impulse to work to obtain food.
Any apparel worn on the foot, such as shoes, boots, sandals, etc.
Investigative information gathered regarding footwear or tire impression(s) beyond, or in lieu of, comparison to a known item.
Pertaining to the use of analytic / scientific techniques to establish or verify identity - inthis standard, it applies to the examination and mark-up of images (sometimes manually).
The application of science to answer questions of interest to the legal system.
A forensic anthropologist is an individual with at least a masters degree in forensic anthropology,biological anthropology, or related field, and who also has forensic anthropology case experience ortraining involving fragmentary, burned, and otherwise taphonomically-altered human skeletalremains. They also must have training or experience in producing a biological profile (age, sex,stature, ancestry), and interpreting human skeletal trauma.NOTE Board-certified forensic anthropologists possess a Ph.D. in forensic anthropology/biologicalanthropology or related field and are certified by the American Board of Forensic Anthropology (ABFA).
A forensic anthropologist is an individual with at least a masters degree in forensic anthropology, biological anthropology, or related field, and who also has forensic anthropology case experience or training involving fragmentary, burned, and otherwise taphonomically-altered human skeletal remains. They also must have training or experience in producing a biological profile (age, sex, stature, ancestry), and interpreting human skeletal trauma. NOTE Board-certified forensic anthropologists possess a Ph.D. in forensic anthropology/biological anthropology or related field and are certified by the American Board of Forensic Anthropology (ABFA).
Forensic anthropology is the application of anthropological methods and theoryparticularlythose relating to the recovery and analysis of human remainsto resolve legal matters.
Forensic anthropology is the application of anthropological methods and theoryparticularly those relating to the recovery and analysis of human remainsto resolve legal matters.
The scientific examination, analysis, comparison, or evaluation of audio.
The scientific examination, analysis, comparison, or evaluation of audio
An autopsy authorized by law, and typically performed under the jurisdiction of a medical examiner or coroner for criminal justice and public health purposes.
Creating a bit stream duplicate of the available data from one physical media to another.
Creating a bit stream duplicate of the available data from one physical media to another
An individual who provides an assessment of an individual's dental age based upon accepted methodology. Note: The term 'practitioner' will be used instead of 'Forensic Dental age assessment Practitioner' throughout this document as an abbreviated way to describe an individual who provides an assessment of an individual's dental age based upon accepted methodology.
The use of DNA technologies for the evaluation of biological evidence that may be involved in legal matters.
See image.
See image
A filtered light source that may be fixed or tunable to a variety of spectral ranges
That part of dentistry, which deals with the examination, interpretation, and presentation of dental and oral evidence for legal purposes.
A physician who is certified in forensic pathology by the American Board of Pathology (ABP) or who, prior to 2006, has completed a training program in forensic pathology that is accredited by the Accreditation Council on Graduate Medical Education or its international equivalent or has been officially 'qualified for examination' in forensic pathology by the ABP.
A physician who is board-certified in anatomic pathology or anatomic and clinical pathology, as well as forensic pathology.
The practice of medicine in which the principles of pathology are applied to problems of potential legal, public health, or public safety significance; a common function is the performance of autopsies to determine the cause of death and assist in determining the manner of death.
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 for criminal and civil law or regulatory issues; and (2) issues test results, provides interpretations, or opinions through reports or testi- mony 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 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 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 organization or individual that provides forensic science services.
Also referenced in ANSI/ASB 017 Standard Practices for Measurement Traceability in Forensic Toxicology, ASTM E1732-22 Standard Terminology Relating to Forensic Science, ANSI/ASTM E2917-19a 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