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 middle segment of the finger. The thumb does not have a medial segment.
An appointed forensic pathologist whose duty is to oversee medicolegal death investigations, perform postmortem examinations, and certify cause and manner of death. In some jurisdictions, individuals with other qualifications hold the title 'Medical Examiner', but for purposes of this document those individuals are considered medicolegal death investigators.
A person or agency charged by law with conducting death investigations for the purpose of certifying deaths.
A formal inquiry into the circumstances surrounding the death of a human being; investigative information is considered with autopsy findings and adjunctive studies (if performed) to determine the cause and manner of death.
Medicolegal death investigation office (usually medical examiner or coroner office) within a state or district that is a jurisdictional unit and, which may have a single chief medicolegal officer.
An individual who performs medicolegal death investigations.
The medicolegal investigation includes the collection of data, photographs, evidence, witness interviews, external examination of the body at the scene, and other forensic information and analysis that will contribute to the identification of decedent, determination of cause and manner of death, reconstruction of the accident or crime scene, and support the provision of survivability factors.
A subclass of ignitable liquid characterized in ASTM E1618-11as a petroleum distillate where the majority of components have a boiling range between that of octane (C8) and tridecane (C13). There will be no major components with a boiling range less than heptane (C7) or greater than tetradecane (C14).
the central portion of a hair composed of a series of discrete cells or an amorphous spongy mass.
The core of the hair shaft that is composed of vacuoles and cells that can be air- or fluid-filled. DiscussionThe medulla (if present) occurs in a continuous, discontinuous, or fragmented pattern along the length of a hair and appears translucent or opaque.
The central portion of a hair composed of a series of discrete cells or an amorphous spongy mass
the core of the hair shaft that is composed of vacuoles and cells that can be air- or fluid-filled.
Discussion—The medulla (if present) occurs in a continuous, discontinuous, or fragmented pattern along the length of a hair and appears translucent or opaque.
In computer forensics,(1) hardware used for the temporary storage of operating instructions and data while a digital device is running; (2) see random access memory.
In computer forensics, (1) hardware used for the temporary storage of operating instructions and data while a digital device is running; (2) see random access memory
In computer forensics, the modification of data by a running system during the memory acquisition process.
In computer forensics, the modification of data by a running system during the memory acquisition process
The level of awareness and response to the environment.
The level of awareness and response to the environment.
The period directly after an FSSP has been authorized to perform technical review and verification casework by their organization. During the period of mentorship the FSSP shall work with guidance from an experienced FSSP when necessary. As the level of confidence in the new FSSPs ability to independently perform casework increases, the amount of contact time with the mentor gradually decreases. The number of cases under which mentored casework is performed will be determined by the trainer.
Documentation relevant to the biometric data, but not the biometric data itself.Metadata may include both signal/sample-related and content-related information.Examples are the format of the data file, such as WAV and the scope of accreditation ofa DNA processing laboratory.
Data, frequently embedded within a file, that describes a file or directory.
Data, frequently embedded within a file, that describes a file or directory
Two colors that appear the same under one illumination, but different under other illumination
Two or more samples that appear to have the same color under one type of illumination but can appear dissimilar under different lighting conditions, or two or more samples that appear to be the same color under all lighting conditions, yet their reflectance/transmittance spectral curves are different.
Two or more samples that appear to have the same color under one type of illumination but can appear dissimilar under different lighting conditions, or two or more samples that appear to be the same color under all lighting conditions, yet their reflectance/transmittance spectral curves are different
when colors are perceived to be matching despite having different spectral profiles.
A combination of procedural steps used to perform a specific technical process. The method includes the validated steps, reagents, and critical instruments needed to perform the process or portion of a process. The same method may be conducted using different equipment (automated vs manual) when appropriately validated.1
A quantitative procedure by which a known concentration of the target analyte is added to multiple aliquots of the case sample(s)
Methodology refers to the categories of methods used to perform a stage of a DNA typing technology or technologies. For example, methodologies for STR technology can include extraction, quantification, amplification, and detection.
property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of comparisons, each contributing to the measurement uncertainty (see 2.4.1 of International Vocabulary of Metrology (VIM) Basic and General Concepts and Associated Terms [10]).
Military Grid Reference System
A chart relating thickness, birefringence, and retardation so that any one of these variables can be determined when the other two are known
a chart relating thickness, birefringence, and retardation so that any one of these variables can be determined when the other two are known.
the decomposition of petroleum products in fire debris by bacterial action that can diminish some compounds, resulting in an altered pattern in a chromatogram.
An implant that is placed under the skin of an animal that provides a unique electronic identification.
An implant that is placed under the skin of an animal that provides a unique electronic identification.
A small drop of liquid that would fit on the end of a standard size, flattened toothpick; the approximate volume of this drop would be 10 to 25 L.
A small drop of liquid that would fit on the end of a standard size, flattened toothpick; the approximate volume of this drop would be 10 to 25 L.
A small drop of liquid that would fit on the end of a standard size, flattened toothpick; the approximate volume of this drop would be 10 to 25 L.
A small drop of liquid that would fit on the end of a standard size, flattened toothpick; the approximate volume of this drop would be 10 to 25 L
a term that describes characteristics too small to be resolved by the unaided eye, but large enough to be resolved with a microscope.
a term that describes characteristics too small to be resolved by the unaided eye, but large enough to be resolved with a microscope.
concerning a microscope or the use of a microscope.
Concerning a microscope or the use of a microscope
concerning a microscope or the use of a microscope.
A specialized spectrophotometer designed to measure the absorbance, reflectance and emission spectra of microscopic areas on samples.
A specialized spectrophotometer designed to measure the absorbance, reflectance and emission spectra of microscopic areas on samples
Sample preparation approach that sequentially passes a blade at a shallow depth through a sample resulting in sections of selected thickness as well as a flat block
A sample preparation method that sequentially passes a blade at a shallow depth through a specimen, resulting in sections of selected thickness.
Sample preparation approach that sequentially passes a blade at a shallow depth through a sample resulting in sections of selected thickness as well as a flat block.