Forensic Science - ANSApplication of science to the criminal and civil laws that are enforced by
police agencies in a criminal justice system.
An umbrella term encompassing a myriad of professions that use their skills to aid law
enforcement officials in conducting their investigations. (Criminalistics, digital and multimedia
sciences, engineering science, general, juisprudence, odontology, pathlogy/biology, phycial
anthropology. psychiatry/behavioral science, questioned documents, toxicology)
Locard's Exchange Principle - ANSWhenever two objects come into contact with one another,
there is exchange of materials between them.
Scientific Method - ANSA process that uses strict guidelines to ensure careful and systematic
collection, organization, and analysis of information.
Expert Witness - ANSAn individual whom the court determines to possess knowledge relevant
to the trial that is not expected of the average layperson.
Physical Evidence - ANSAny object that can establish that a crime has or has not been
committed or can link a crime and its victim to its perpetrator.
Rough Sketch - ANSA draft representation of all essential information and measurements at a
crime scene. This sketch is drawn at the crime scene.
Finished sketch - ANSA precise rendering of the crime scene, usually drawn to scale.
Chain of Custody - ANSA list of all people who came into possession of an item of evidence.
Standard/Reference Sample - ANSPhysical evidence whose origin is known, such as fibers or
hair from a suspect, that can be compared to crime-scene evidence.
Buccal Swab - ANSA swap of the inner portion of the cheek; cheek cells are usually collected to
determine the DNA profile of an individual.
Substrate Control - ANSUncontaminated surface material close to an area where physical
evidence has been deposited. This sample is to be used to ensure that the surface on which a
sample has been deposited does not interfere with laboratory tests.
Identification - ANSThe process of determining a substance's physical or chemical identity. Drug
analysis, species determination, and explosive residue analysis are typical examples of this
undertaking in a forensic setting.
, Comparison - ANSThe process of ascertaining whether two or more objects have a common
origin.
Individual Characteristics - ANSProperties of evidence that can be attributed to a common
source with an extremely high degree of certainty.
Class Characteristics - ANSProperties of evidence that can be associated only with a group and
never with a single source.
Product Rule - ANSMultiplying together the frequencies of independently occurring genetic
markers to obtain an overall frequency of occurrence for a genetic profile.
Rapid DNA - ANSA process for developing DNA profiles from a buccal swap in 90 minutes or
less that are compatible with a CODIS search.
Crime Scene Reconstruction - ANSThe method used to support a likely sequence of events at a
crime scene by the observation and evaluation of physical evidence and statements made by
individuals involved with the incident.
Satellite Spatter - ANSSmall drops of blood that are distributed around the perimeter of a drop
or drops of blood and were produced as a result of the blood impacting the target surface.
Angle of Impact - ANSThe acute angle formed between the path of a blood drop and the surface
that it contacts.
Impact of Spatter - ANSA bloodstain pattern produced when an object makes forceful contact
with a source of blood, projecting drops of blood outward from the source.
Forward Spatter - ANSBlood that travels away from the source in the same direction as the
force that caused the spatter.
Back Spatter - ANSBlood directed back toward the source of the force that caused the spatter.
Low-Velocity Spatter - ANSAn impact spatter pattern created by a force traveling at 5 feet per
second or less and producing drops with diameters greater than 3 millimeters.
Medium- Velocity Spatter - ANSAn impact spatter pattern created by a force traveling at 5 to 25
feet per second and producing drops with diameters between 1 and 3 millimeters.
High- Velocity Spatter - ANSAn impact spatter pattern created by a force traveling at 100 feet
per second or faster and producing drops with diameters less than 1 millimeter.