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.
Media, Storage Media
Medial Segment
The middle segment of the finger. The thumb does not have a medial segment.
medical examiner
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.
medicolegal death investigation
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 authority
Person or persons whose duty it is to perform medicolegal death investigations for a designated jurisdiction and ensure certification of cause and manner of death; duties vary based on local enabling statutes.
medicolegal death investigation office
Physical location of an agency (usually a medical examiner or coroner office) with the authority to perform medicolegal death investigations.
medicolegal death investigation system
The statutorily established infrastructure (e.g., county coroner or state medical examiner) that exists to conduct medicolegal death investigations within a defined geographic area.
medicolegal death investigator
Individual who performs medicolegal death investigations and includes those who have not completed the requirements for certification and is not certified.
medicolegal significance
Relevant to the medicolegal death investigation system; anthropologically, this term typically refers to human skeletal material of recent origin.
medicolegal significance
Relevant to the medicolegal death investigation system; anthropologically, this term typically refers to human skeletal material of recent origin.
medium
Substance(s) used to create an image or text.
Medulla
Medulla
member/member of a system/member of a scheme
person or organization that is involved in the development, revision or approval of the rules and procedures (5.2) of a conformity assessment system (4.8) or scheme (4.9)
Memory
Memory Smear
Mendelian inheritance
A reference to the basic principles that govern the transmission of genetic traits from parents to offspring discovered by Gregor Mendel in the late 19th century.
Mental State
The level of awareness and response to the environment.
Metadata
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.
Metadata
metadata
Information stored inside an electronic document or image that provides information which may include authorship, editing details, and the computer on which the document was created or modified.
Metameric Samples
Metamerism
metamers (optical and instrumental examination, ink and paper)
Specimens differing in spectral reflectance but having colors that match in light of one spectral composition, when viewed by one observer, but may not match in light of other spectral compositions, or when viewed by another observer. (ASTM E284)
Method
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
method development
process by which analytical parameters are established for a non-standard test method, laboratorydeveloped test method, or standard test method used outside its intended scope (or otherwise modified) that considers sample preparation, instrumental conditions, interpretation of observations, data or calculations, and metrological traceability
method of standard addition (MSA)
quantitative procedure by which known concentrations of target analyte are added to multiple aliquots of the case sample(s)
method validation
process of performing a set of experiments to establish objective evidence that a non-standard test method, laboratory-developed test method, or standard test method used outside its intended scope (or otherwise modified) is fit for purpose and to identify limitations under normal operating conditions
method verification
process by which a laboratory establishes objective evidence of its ability to use a non-standard test method, laboratory-developed test method, or standard test method within its intended scope to achieve the method’s defined performance specifications
Methodology
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.
metric estimation
An estimate based on measurement of skeletal elements.
metrological traceability (measurement traceability)
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
metrological traceability b (measurement traceability)
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
Metrological Traceability, Traceability
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]).
MGRS
Military Grid Reference System
Michel-Levy Chart
Microbial Degradation
Microchip
An implant that is placed under the skin of an animal that provides a unique electronic identification.
Microdrop
Microscopic
Microscopical
Microspectrophotometer (MSP)
Microtomy
Microtomy
Mid-infrared
Midsole
Migration
Mikrosil
Min
Minute (of time)