A chemical transformation in which heat energy is absorbed from the surroundings.

A technique by which DNA fragments are placed in a gel and charged with electricity. The process separates the fragments by size, as part of the process of creating a genetic profile.

The process of testing to identify DNA patterns or types. In forensic science this testing is used to indicate parentage or to exclude or include individuals as possible sources of bodily fluid stains (blood, saliva, semen) and other biological evidence (bones, hair, teeth.)

Databases which store DNA profiles collected from various classes of offenders. DNA from a given crime can be entered into the databank; it can then be matched with DNA profiles from other crimes, providing potential matches from previous convictions.

Deoxyribonucleic Acid. Constructed of a double helix, DNA is the genetic material contained in cells. All organic matter has a specific DNA sequence; these sequences act like a genetic fingerprint and are currently the best method for identifying organic evidence like blood and other bodily fluids.

A microscopic, single-cell form of marine or fresh-water algae, having siliceous cell walls. A body of water may contain many specifies of diatoms, but not all species of diatoms live in every body of water. Through painstaking examination, forensic scientists are able to identify the body of water wherein a given specifies of diatom lives.

The study of criminal activity and how it is dealt with by the law.

A tool used to aid investigators by providing information about the type of individual committing a specific crime. Information taken from the crime scene is integrated with known psychological theory and the history and background of the victim to draw up a biographical sketch of the perpetrator.

The attempt by a perpetrator or accomplice to alter a crime scene in order to reduce its evidentiary value.