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.
precision
The degree of mutual agreement among a series of individual measurements, values and/or results.
precision
measure of the closeness of agreement between a series of measurements obtained from multiple samplings of the same or similar homogenous samples
precision b(Mod)
Measure of the closeness of agreement between a series of measurements obtained by replicate measurements on the same or similar samples
Precision Studies
Studies performed to evaluate the variation in likelihood ratios calculated from repeated software analyses of the same input data using the same set of conditions/parameters. Probabilistic genotyping systems inherently do not produce the same exact numbers in repeated analysis. These studies should demonstrate the range of values that can be expected from multiple analyses of the same data
precursor ion(modified)
ion that reacts to form particular product ions or undergoes specified neutral losses
prefix
The portion of the check writer impression located immediately to the left of the numeric value. (SWGDOC E07)
Premixed Flame
A flame for which the fuel and oxidizer are mixed prior to combustion, as in a laboratory Bunsen burner or a gas cooking range; propagation of the flame is governed by the interaction between flow rate, transport processes, and chemical reaction.
Prenatal Dental Age Interval
The interval in human development that occurs prior to birth.
Preservation
Application or use of measures to prevent damage, change or alteration, or deterioration.
Preservation
The intentional act to prevent damage, contamination, alteration, or deterioration of anything contained within a scene.
Preservation
Pressed Outsole
Pressure-Sensitive Adhesive
Pressure-Sensitive Adhesive (PSA)
Pressure-Sensitive Adhesive (PSA) Tape
Pressure-Sensitive Adhesive (PSA) Tape
presumptive positive
analytical result that, on its own, does not achieve the minimum points for the identification of a substance
NOTE See ANSI/ASB Standard 113: Standard for Identification Criteria in Forensic Toxicology for a complete discussion of identification points.
Presumptive Test
A screening test that indicates the possible presence of a material of interest. A positive presumptive test result does not constitute the identification of that material. A negative presumptive test indicates that the material of interest was not detected; it is not confirmation of its absence. Presumptive tests are sensitive but not specific and can lead to false positive results.
Presumptive Test
A screening test which may be positive in the presence of a biological material of interest. Some presumptive tests are sensitive but not specific. A positive result indicates that further testing could be informative.
preventive action
Action to eliminate the cause of a potential non-conformity or other potential undesirable situation. NOTE A preventive action is taken to prevent occurrence whereas a corrective action is taken to prevent recurrence.
Prill
primary examiner
The initial examiner conducting the forensic examination, recording their source conclusions, and authoring a report of their findings.
Primary Explosive
Primary Image
primary image
The first instance in which an image is recorded onto any media that is a separate, identifiable object (for example, a digital image recorded on flash media). (SWGDOC D01)
primary indentation
An impression on a document(s) or other substrate(s) beneath the originating document caused by the act of writing or other dynamic actions. (ANSI/ASB Std 044)
Primary Reinforcement
The delivery of a naturally occurring stimulus that requires no previous experience or learning to be reinforcing. It satisfies some biological need (i.e., food, water, air, social interaction).
Prime Coat
Primed Cartridge Case
A cartridge case containing only a primer, without propellant or projectile.
Primer
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.
Primer
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.
primer
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 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.
Primer
Primer Cap
Primer GSR
primer gunshot residue (pGSR)
A subcategory of gunshot residue considering only chemicals generated from the priming mixture. Typically composed of very small particles containing lead, barium, and antimony, and detected using scanning electron microscopy.
primer peak
Fluorescence from unincorporated PCR primers present in amplified DNA product that is detected before the sizing range in an electropherogram.
primers
Short polynucleotide sequences which target a specific region of template DNA and allow a DNA polymerase to initiate synthesis of a complementary strand.
principal trainer
Person with the primary responsibility for the training program administered to an individual.
Print Data
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.
printer
Output device that produces a hardcopy record of data in the form of a sequence of discrete graphics belonging to a predetermined character or image set.
printer output area
Maximum area on the page to which the printer will print. (ASTM F1457)
Printer's Ink
printhead
Printing device of an ink jet or thermal printing system.
printing element
The parts of the total checkwriter impression that are not parts of the prefix which may encompass the currency type, decimal points, and commas. (SWGDOC E07)
printing medium
A substance used to create an image, such as printing ink, toner, or wax.
printing module
Those components in the laser printer that together drive the laser scanner, create the image on the page, and deliver the page to the stacker.
Prior Data
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.
private autopsy
Autopsy requested and authorized by next of kin.