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.
An estimate of the lowest concentration of an analyte in a sample that can be reliably differentiated from blank matrix and identified by the analytical method
An estimate of the lowest concentration of an analyte in a sample that can be reliably measured with acceptable bias and precision
An estimate of the lowest concentration of an analyte in a sample that can be reliably measuredwith acceptable bias and precision.
Estimate of the lowest concentration of an analyte in a sample that can be reliably measured with acceptable bias and precision
Estimate of the lowest concentration of an analyte in a sample that can be reliably measured with acceptable bias and precision.
estimate of the lowest concentration of an analyte in a sample that can be reliably measured with acceptable bias and precision
An estimate of the lowest concentration of an analyte in a sample that can be reliably measured with acceptable bias and precision.
The seven vertebrae between the ribs and the pelvis.
The seven vertebrae between the ribs and the pelvis.
the cavity or central canal present in many natural fibers (for example, cotton, flax, ramie, jute, hemp); its presence and structure are often useful aids in identification.
the gloss or shine possessed by a fiber, resulting from its reflection of light; the luster of manufactured fibers is often modified by use of a delustering pigment.
The unit of illuminance and luminous emittance, measuring luminous flux per unit area.It is equal to one lumen per square meter
A companding algorithm used in North America and Japan that optimizes an analog telephone band signal while digitizing.
Media Access Control address, a unique identifier assigned to network interfaces.
the direction of the tape that runs the length of the tape.
a nominal resolution specification for a flatbed scanner based on the actual number of pixels per inch in the sensor array and the number of individual steps per inch that the stepper motor can move the sensor array. This is to be distinguished from the maximum resolution specification that is based on resampling. This is also called optical resolution.
a term that describes characteristics large enough to be perceived without magnification.
The size, strength, or duration of a reward following a behavior.
the final explosive in an explosive train.
Continuing training conducted beyond the initial training of a discipline, designed to maintain a level of proficiency by ensuring the canine team's capability to perform desired tasks.
Continuing training conducted beyond the initial training of a discipline, designed to maintain a level of proficiency by ensuring the canine team's capability to perform desired tasks.
Continuing training conducted beyond the initial training of a discipline, designed to maintain a level of proficiency by ensuring the canine team's capability to perform desired tasks.
Classification system based on the circumstances under which death occurred and any available postmortem findings, as known to the MDI authority at the time of certification; usually consists of accident, homicide, natural, suicide, and undetermined. Manner of death classification is a statutory function of the medicolegal death investigation authority, as part of death certification for purposes of vital statistics and public health, and does not imply a legal or judicial conclusion.
Classification system based on the circumstances under which death occurred; includes accident, homicide, natural, suicide, and undetermined.
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 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.
An anomaly produced during the die’s manufacturing process resulting in a damaged area creating a non-print area in the impression. This is often referred to as a permanent defect.
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; used as a point of reference in the mapping of other loci.
A gene or specific DNA sequence of known location on a chromosome or genome.
automated function where results above or below a specified threshold are reported with a defined result. For example, the instrument may report “ethanol below administrative threshold” or “0.000 g/210 L ethanol” for a response below 0.005 g/210 L. Another example may be reporting “Results greater than 0.400 g/210 L” or “Over Range” for a response above 0.400 g/210 L.
The presence of an odor/scent that impedes detection of the target odor/scent source.
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).
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.
Any genetic information passed from the mother to the offspring.
A specific biological fluid or tissue. Examples include blood, plasma, serum, urine, vitreous fluid, hair, and tissue.
the physical material, such as burned debris or clothing, which is being tested for ignitable liquids; also known as substrate.
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