OSAC Lexicon

The chronological documentation or paper trail, showing the seizure, custody, control, transfer, analysis, and disposition of physical or electronic evidence.

A characteristic pattern of behaviors, as interpreted by the canine handler that occurs when the canine detects a trained odor/scent. This differs from other olfactory interest that otherwise are exhibited by the canine in response to the daily environment. The initial change of behavior typically leads to following the odor/scent to its source/target. The pattern of behavior may be unique to each canine. (See interest.)

Carbonaceous material that has been burned or pyrolyzed and has a blackened appearance.

Convex segments of carbonized material separated by cracks or crevasses that form on the surface of char, forming on materials such as wood as the result of pyrolysis or burning.

Any language symbol (for example, letter, numeral, punctuation mark, or other sign), other symbol, or ornament. (SWGDOC E01)

The number of characters that can be printed in a horizontal 1 in. (25.4 mm). (ASTM F1457)

The width allotted to each character in a fixed pitch (monospacing) typewriter or to the basic unit in a proportional spacing typewriter; usually expressed in millimeters or as a fraction of an inch. (SWGDOC E04)

A feature, quality, attribute, or property of an item. (SWGDOC E01)

particles which exhibit properties associated with the detonation of a percussion primer and for which there are no other known sources that reproducibly yield particles exhibiting all of the same properties.

A feature found in handwriting that is not attributable to a class of writing and it is not taught. Only in combination would this characteristic(s) distinguish class from non-class.

A deviation from a class characteristic that would be present only by chance in another member of the class.

A feature determined prior to manufacture that is intended to be present in a particular form in every member of a group and can be used to define that group (e.g., a copybook style of writing, a specific type style, print process).

A feature found in a similar, but not necessarily exact, form in the handwriting of individuals who are not members of a definable group and is not attributable to the study of a particular handwriting system.

A feature found in a similar, but not necessarily exact, form in the handwriting of individuals who are mem

A feature, determined prior to manufacture, that is intended to be present in a particular form in every member of a sub-group within a class and can be used to define that sub-group.

A feature found in an individual’s handwriting that is attributable to the study of a particular handwriting system.

A feature or defect that can be modified over time or removed entirely by use, cleaning, replacement, or repair.

An attribute or combination of attributes that are variably acquired with the potential to differentiate a single member of a particular class, category, or group.

Also referenced in ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science.
 

An attribute or combination of attributes with the potential to establish membership in, but are unable to differentiate a single member of, a particular class, category, or group.

Also referenced in ANSI/ASTM E1732 Standard Terminology Relating to Forensic Science. 

Comprises the components of the test, the procedure used, limitations of the test, and the methods for detection and analysis including whether the test is presumptive or confirmatory and the type of body fluid, stain, or residue being targeted.

Document(s) damaged by heat or fire. (ANSI/ASB Standard 127).

Items damaged by heat or fire. (SWGDOC P01)

A device manually or electrically powered or computer generated, designed to ink, emboss, print, perforate, or shred a monetary value, along with other peripheral information, onto a document. (SWGDOC E07)

A method of DNA extraction involving Chelex resin; since one step of the method requires boiling, the extracted DNA is single-stranded.

Medical examiner, coroner, justice of the peace or other official who oversees the operation of a medicolegal death investigation office and/or system.

The vertical airflow within buildings caused by the temperature-created density differences between the building interior and exterior or between two interior spaces. Also known as the stack effect.

The effect of heat on odor/scent such that the odor/scent rises and travels through the air in a manner affected by air movement and temperature through convection. The end effect is that odor/scent is detected in a place that is different from the source. This can happen indoors or outdoors.

An organic compound containing chlorine atoms.

A physical method of separation in which the components to be separated are distributed between two phases, one of which is stationary (stationary phase) while the other (the mobile phase) moves in a definite direction.

physical method of separation in which the components to be separated are distributed between two phases, one of which is stationary (stationary phase) while the other (mobile phase) moves in a definite direction

A method of separating substances that is widely used in analytical and preparatory chemistry. It involves the flow of a liquid or gas mobile phase over a solid or liquid stationary phase. As the mobile phase flows past the stationary phase, a solute will undergo repeated adsorption and desorption and move along at a rate depending, among other factors, on its ratio of distribution between the two phases. If their distribution ratios are sufficiently different, components of a mixture will migrate at different rates and produce a characteristic pattern (chromatogram). (SWGDOC M01)

The difference between the individual's date of birth and a specific later date. Note: Chronologic age may be expressed in varying degrees of precision and can be derived from computer programs that report age values using multiple significant digits. To correctly interpret and report results, consultation with a statistician may be necessary.

The age of an individual in years, months, and/or days, calculated as the difference between the individual’s date of birth and a specific later date.

The International Commission on Illumination. The color space that they defined iscalled CIELab. They have also developed a metric for color distance called E1976(Delta E) with 1976 indicating the version of the formula. They have developed moredetailed and precise distance metrics in later years. For more information, seehttp://en.wikipedia.org/wiki/Color_difference.

Ratio of a single ink dot height divided by its width with 1.0 being a perfect circle. (ASTM F1857)

The Criminal Justice Information Services Division of the FBI.