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.
Classification system based on the circumstances under which death occurred; includes accident, homicide, natural, suicide, and undetermined.
See photographic comparison.
See photographic comparison
a class name for various genera of filament, tow, or staple produced from fiber-forming substances which can be (1) polymers synthesized from chemical compounds, (2) modified or transformed natural polymers, or (3) glass.
Discussion—Acrylic, nylon, polyester, olefin, urethane, and polyvinyl are examples of fiber synthesized from chemical compounds. Cellulose-based fibers, such as acetate and rayons, and alginate fibers are examples of modified or transformed polymers.
a class name for various genera of filament, tow, or staple produced from fiber-forming substances which can be (1) polymers synthesized from chemical compounds, (2) modified or transformed natural polymers, or (3) glass.
a class name for various genera of fibers (including filaments) produced from fiber-forming substances which can be (1) polymers synthesized from chemical compounds [synthetic fibers], (2) modified or transformed natural polymers [regenerated fibers], and (3) minerals, for example, glasses.
A class name for various genera of fibers (including filaments) produced from fiber-forming substances which can be (1) polymers synthesized from chemical compounds [synthetic fibers], (2) modified or transformed natural polymers [regenerated fibers], and (3) minerals, for example, glasses
Unintended damage, defects or flaws in the footwear outsole or tire tread that occurs during manufacturing, which depending on their cause, could result in class or randomly acquired characteristics.
Features that occur during the manufacturing process that do not appear on all of the footwear/tires but may appear on more than one. Examples would be the precise positioning of foxing strips, the precise cutting of die cut or Wellman cut soles, the positioning of stitching that is added to the bottom of some soles, or a bent sipe blade in a tire mold, etc.
The point where a needle has pierced the skin, usually associated with drug use.
A colored grain of smokeless powder to assist in the visual identification of a bulk reloading smokeless powder
A gene or specific DNA sequence of known location on a chromosome or genome.
The presence of an odor/scent that impedes detection of the target odor/scent source.
A standard having the highest metrological quality available at a given mass, from which the measurements made at that mass are derived
The mass of an ion divided by its charge.
One of a number of high throughput DNA sequencing techniques. Also referred to as Next Generation Sequencing (NGS).
One of a number of high throughput DNA sequencing techniques. Also referred to as Next Generation Sequencing (NGS).
The original retrieved data irrespective of media (for example, if the recorded video from the DVR hard drive was downloaded to CD/DVD, that CD/DVD is defined as the master).
The original retrieved data irrespective of media (for example, if the recorded video from the DVR hard drive was downloaded to CD/DVD, that CD/DVD is defined as the master)
The determination that two samples are not distinguishable from each other given available data and/or information. When used in a DNA testing report, a match refers to genetic profiles that show the same types at all loci tested in common; a match statement does not confirm that an individual is the source of the DNA.
A mathematical value that indicates the degree of similarity between an unknown spectrum and a reference spectrum.
A mathematical value that indicates the degree of similarity between an unknown spectrum and a reference spectrum.
A pathway laid by a human subject whose scent matches the scent on the article presented to the canine.
A procedure where upon presentation of a comparison stimulus, an animal chooses the same stimulus amongst an array of stimuli. For example, a canine is presented with scent of Person X and then identifies the scent contributor amongst an array of persons.
The fuel that is first set on fire by the heat of ignition; to be meaningful, both a type of material and a form of material should be identified.
the physical material, such as burned debris or clothing, which is being tested for ignitable liquids; also known as substrate.
A specific biological fluid or tissue. Examples include blood, plasma, serum, urine, vitreous fluid, hair, and tissue.
dominant or background color component of a soil sample, soil aggregate, ped, clod, or horizon.
A positive or negative control that is prepared in the same or similar matrix as the case sample(s) or material
Megabyte (of digital storage) this normally refers to 1024*1024 (1,048,576) bytes in digital applications thoughothers may intend 1000*1000 or 1,000,000 bytes.
A widely used cryptographic hash function producing a 16-byte hash value, typically expressed in text format as a32-digit hexadecimal number. MD5 is commonly used to verify data integrity.
Medical examiner or coroner
A characteristic which demonstrates the particular known footwear or tire was not the source of the impression.
A feature or property of a sample that does not fall within the variation exhibited by the comparison sample, considering the limitations of the sample or technique, and therefore indicates the two samples do not share a common origin.
A feature or property of a sample that does not fall within the variation exhibited by the comparison sample, considering the limitations of the sample or technique, and therefore indicates the two samples do not share a common origin. The use of this term does not imply the formal application of statistical tests
A feature or property of a sample that does not fall within the variation exhibited by the comparison sample, considering the limitations of the sample or technique, and therefore indicates the two samples do not share a common origin. The use of this term does not imply the formal application of statistics.
A feature or property of a sample that does not fall within the variation exhibited by the comparison sample, considering the limitations of the sample or technique, and therefore indicates the two samples do not share a common origin. The use of this term does not imply the formal application of statistics.
Quantity intended to be measured. VIMa
quantity intended to be measured
A physical quantity or property which is measured.
Make a measurement.
System of coordinates that represent the geometry of the measured surface.NOTE If the nominal surface is a plane (or portion of a plane), it is common to use a rectangular coordinatesystem in which the axes form a right-handed Cartesian set, the X-axis being the direction of tracing co-linearwith the mean line, the Y-axis also lying on the nominal surface, and the Z-axis being in an outward direction(from the material to the surrounding medium).
Property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty
Non-negative parameter char- acterizing the dispersion of the quantity values being attrib- uted to a measurand, based on the information used
Element in the optical path of a MSP system that limits the area of illumination reaching the detector focal plane.
Element in the optical path of a MSP system that limits the area of illumination reaching the detector focal plane
The process of inspecting, identifying, and noting the properties of media.
The process of inspecting, identifying, and noting the properties of media
Objects on which data can be stored.
Objects on which data can be stored