OSAC Lexicon

Visual (macroscopic) assessment of skeletal remains.

A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and earth or to some conducting body that serves in place of the earth.

A current that flows outside the normal circuit path, such as (1) through the equipment grounding conductor; (2) through conductive material in contact with lower potential (such as earth), other than the electrical system ground (metal water or plumbing pipes, etc.); or (3) through a combination of these ground return paths.

Information that is known to be real or true, provided by direct observation and measurement (i.e., empirical evidence) as opposed to information provided by inference.

A document that is advisory or informative in nature and that contains only nonmandatory provisions. A guide may contain mandatory statements such as when a guide can be used, but the document as a whole is not suitable for adoption into law.

A signature executed while an impaired writer's hand, arm, or writing instrument is controlled by another resulting in a distorted signature. See assisted hand signature.

Recommended practice that allows some discretion or leeway in its interpretation, implementation, or use. A set of general principles used to provide direction and parameters for decision making.

Lines that show a route to follow when simulating handwriting or signatures. These can exist in the form of pencil lines or indentations or be created by the use of transmitted light shone through a document containing the entries to be copied. (NIST HF)

The total of all residues resulting from the discharge of a firearm. 

NOTE Examination of GSR can include chemical analysis to identify the presence of GSR or interpretation of GSR patterns to determine the location or position of a firearm at the time of discharge.

The lessening or disappearance of a response that was once elicited by the stimulus with repeated presentation of the same or closely related stimulus.

The thinnest line found in a specific typeface that consists of lines of varying widths, usually common to serif typefaces.

Print process in which a series of dots of variable diameter and regular interdot spacing is used to print photographs and drawings.

A style of writing in which the letters are not joined and the writing instrument is lifted after most strokes. (SWGDOC T01)

The handler is a person who has successfully completed a documented training and certification process in canine handling in the specific discipline of ignitible liquid canine detection and maintains those abilities through field application, maintenance training, scheduled recertification, and continuing education. (See 3.4.2, Certification.) [SC1, 2011].

See canine handler.

Any action or cue made by the handler that causes the canine to perform incorrectly. (See canine handler error.)

Writing in any form (such as cursive, hand printing, signatures, numbers). Although "handwriting," is used as a general term, it may be produced by the hand, mouth, foot, or other body part by directly manipulating a writing instrument.

A group of similar haplotypes that share a common ancestor with a single-nucleotide polymorphism mutation.

A set of linked DNA variations, or polymorphisms, that tend to be inherited together (e.g., commonly used for human Y-chromosome or mitochondrial analysis). A haplotype can refer to a combination of alleles or to a set of single nucleotide polymorphisms (SNPs) found on the same chromosome.

A set of linked DNA variations, or polymorphisms, that tend to be inherited together (e.g. commonly used for mitochondrial or Y-chromosome analysis). A haplotype can refer to a combination of alleles or to a set of single nucleotide polymorphisms (SNPs) found on the same chromosome.

A set of linked DNA variations, or polymorphisms, that tend to be inherited together; a combination of alleles or a set of single nucleotide polymorphisms (SNPs) found on the same chromosome.

A state in which allele and single locus genotype frequencies do not change (on average) from one generation to the next in a population. When alleles in a population are independent, allele and genotype frequencies are related through the Hardy-Weinberg principle: for a locus with 2 alleles P and Q at frequencies of p and q, homozygotes for P are found at frequency p2, homozygotes for Q are found at a frequency of q2, and heterozygotes are found at a frequency of 2pq. Use of the theta correction removes the need to assume Hardy-Weinberg equilibrium in the population for which a frequency database is constructed.

A condition that presents the potential for harm or damage to people, property, or the environment.

A substance (solid, liquid, or gas) that when released is capable of creating harm to people, the environment, and property.

Any material that is an air-reactive material, flammable or combustible liquid, flammable gas, corrosive material, explosive material, organic peroxide, oxidizing material, radioactive material, toxic material, unstable material, biological material or water-reactive material, and any substance or mixture of substances that is an irritant or a strong sensitizer or that generates pressure through exposure to heat, decomposition, or other means.

The vapor surrounding a specific source of interest or investigation.

A form of energy characterized by vibration of molecules and capable of initiating and supporting chemical changes and changes of state.

An arrow used in a fire scene drawing to show the direction of heat, smoke, or flame flow.

The measure of the rate of heat transfer to a surface, expressed in kilowatts/m2, kilojoules/m2 sec, or Btu/ft2 sec.

The heat energy that brings about ignition.

The rate at which heat energy is generated by burning.

The exchange of thermal energy between materials through conduction, convection, and/or radiation.

The exchange of thermal energy between materials through conduction, convection, and/or radiation.

A three-dimensional topographic data set consisting of surface points (x, y, z) where each dimension is a coordinate measured in standard units (e.g., micrometers). See 3.14 topography data.

The study of blood in health and disease.

A pause in the writing without the instrument being lifted. (SWGDOC T01)

The presence of more than one mitochondrial DNA (mtDNA) sequence or type within a single individual.

The presence of more than one mitochondrial DNA (mtDNA) sequence or type within a single individual.

The presence of more than one mitochondrial DNA sequence or type within a single individual.

The presence of more than one mitochondrial DNA (mtDNA) sequence of type within a single individual.

In cursive writing, a space caused by lifting the writing instrument at the conclusion of one letter, followed by the reapplication of the instrument to begin the next letter of a word; also referred to as a break or pen lift. May be an individualized habit.

Credit: Academy Standards Board