Any object that can establish that a crime has or has not been committed, or link an individual to a crime.
Standard Reference Sample
Physical evidence whose origin is known, such as blood or hair from a suspect.
Uncontaminated surface material close to an area where physical evidence has been posited.
The process of determining a substances physical or chemical identity ex: drug analysis
Properties of evidence that can be attributed to a common source with an extremely high degree of certainty.
Properties of evidence that can be associated only with a group, not one thing.
An individual who investigates sudden, unnatural, unexplained, or violent deaths.
Settling of blood after death, the blood is most abundant in areas closest to the ground due to gravitational pull.
The behaviorof a substance when it reacts orcombines with another substance. Chemical reactions
A crack in the glass that extends outward like a spoke of a wheel from where it was struck.
Any of several analytical techniques for sparating organic mixtures. There is a stationary and a mobile phase.
A technique for separating molecules through migration on a support medium while under the influence of an electrical potential.
The number of waves that pass a given point per second. Shorter wavelength means a higher frequency.
The entire range of radiation energy from the most energetic to the least energetic. The rainbow is the magnetic spectrum.
An acronym for light amplification by stimulated emission of radiation. The light is a beam of unison pulse.
A small packet of electromagnetic radiation energy. Each photon contains a unit of energy equal to the product of Planks Constant.
An image that cannot be seen directly. It can be seen only by a viewer looking through a lens.
Illumination of a specimen from above; in microscopy it is used to examen opaque specimens.
Describes a microscope such that when an image is focused with one objective in position the other objective can be rotated into place.
Physiological need for a drug that has been brought about by its regular use. Dependence is characterized by withdrawls sickness when administration of the drug is abruptly stopped.
A substance that depresses the functions of the central nervous system, depressants calm irritability and anxiety and may induce sleep.
Tests to identify specific substances by the color and morphology of the crystals formed when the substance is mixed with specific reagent.
Passage of alcohol across the wall of the stomach and stomach and small intestine into the bloodstream.
Elimination of alcohol from the body in an unchanged state; alcohol is normally excreted in breath and urine.
A tiny blood vessel across whoce walls exchange of materials between the blood and the tissues take place; recieves blood from arteries.
Small sacs in the lungs through whose walls air and other vapors are exchanged between breath and the blood.
To transform a chemical in the body to another chemical to facilitate its elimination from the body.
A scale used to express the basicity or acidity of a substance; pH neutral 7, 1-7 acid. 7 + Base.
A rod like structure in the cell nucleus, along which the genes are located, composed of DNA.
A substance composed of a large number of atoms; these atoms are usually arranged in repeating monomers.
The unit of DNA consisting of one of four bases Adenine, Guanine, Cytosinge, Thymine, they are phosphate sugar groups.
Complementary Base Pairing
The DNA helix strands have matching pairs of phosphate sugar groups. A+T C+G
polymers of amino acids that play basic roles in the structures and functions of living things.
The total DNA content found withi the nucleus of a human cell; three billion base pairs.
Polymerase Chain Reaction
A technique for replication or copying a portion of DNA strands outside a living cell.
The process of joining two complementary strands of DNA to form a double stranded molecule.
A region of a chromosome that contains multiple copies of a core DNA sequence that are arranged in repeating fashion.
Restriction Fragment Length Polymorphism
Different fragment length of base pairs that result from cutting a DNA molecule with restriction enzymes.
Short Tandem Repeat
A region of a DNA molecule that contains short segments consisting of three to seven repeating base pairs.
The outher layer of skin cells, these DNA bearing cells often fall off of or are rubbed off onto objects retrieved from crime scenes.
Crime Scene Reconstruction
Method used to support a likely sequence of events at a crime scene by observation ect.
Small droplets 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
The acute angle formed between the path of a blood drop and the surface that it contacts.
A bloodstain pattern produced when an object makes forceful contact with a source of blood, projecting drops of blood outward from the source.
Blood that travels away from the source in the same direction as the force that caused it.
Low Velocity Spatter
An impact spatter pattern caused by a force traveling at five feet per second or less and producing drops with diameters greater than 3 mm.
Medium Velocity Spatter
An impact spatter pattern created by a force traveling at five to twenty five feet per second.
High Velocity Spatter
An impact spatter pattern created by a forc traveling at 100 feet per second or faster and producing drops less than 1 mm.
Area of Convergence
The area on a two dimensional plane where lines traced through the long axis of several individual bloodstains meet.
Area of Origin
The location in three dimensional space that blood that produced a bloodstain originated. Impact and angle are used to determine the origin.
A bloodstain pattern that is created when blood is flung from a blood bearing object into motion onto a surface.
A characteristic bloodstain pattern containing spurts that resulted from blood exiting under pressure from an arterial joint.
Expirated Blood Pattern
A pattern created by blood that i expelled out of the nose, mouth, or respitory system as a result of air pressure/flow
An area within a deposited spatter pattern that is clear of spatter, caused by an object or person blocking the area at the time of the splatter.
A bloodstain pattern created when a surface that carries wet blood comes in contact with a second surface.
A bloodstain pattern formed by the movement of small or large amonts of blood as a result of gravitys pull.
The process by which the edges of a stain dry to the surface in a specific perid of time on enviormental and surface.
Drip Trail Pattern
A pattern of bloodstains formed by the dripping of blood off a moving surface or person in a recognizable pathway, it's different from other patterns.
A translucent piece of tissue surrounding the hairs shaft near the root it contains the richest source of DNA associated with hair.
DNA present within the nucleus of a cell this form of DNA is inherited from both parents.
Fibers derived from either natural or synthetic polymers the fibers are typically made by forcing material through a spinneret.
A substance composed of a large number of atoms these atoms are usuallly arranged in repeating units of monomers.
A chemical or mechanical action caused by combustion, accompanied bycreation of heat and rapid expansion of gases.
A very rapid oxidation reaction accompanied by the generation of a low intensity pressure wave that can disrupt the surroundings.
An extremely rapid oxidation reaction accompanied by a violent disruptive effect and an intense, high speed shock wave.
A cord containing a core of black powder, used to carry a flame at a uniform rate to an explosive charge.
An explosive with a velocity of detonation greater than one thousand meters per second.
A verbal description of a perpetrators physical charachteristics and dress provided by a witness.
A system of identification of individuals by measurement of parts of the body, created by Alphonse Bertillon
Ridge endings, bifurications, enclosures, and other ridge details, which must match two fingerprints for a common origin to be established.
A fingerprint made by the deposit of oils and or perspiration, invisible to the naked eye.
A class of fingerprints characterized by ridge lines that enter from one side of the pattern and curve around the exit from the same side of the pattern.
A class of fingerprints that includes ridge patterns or circular in shape and have two deltas.
A class of fingerprints characterized by ridge lines that enter the print from one side and flow to the other.
An inkless device that captures the digital images of fingeprints and palm prints electronically transmits the images to AFIS.
A fingerprint made when the finger deposits a visible material such as ink/dirt/blood. ect.
The spiral grooves formed in the bore of a firearm barrel that impart spin to the projectile when fired.
The mechanism in a firearm by which a cartridge of a fired case is withdrawn from the chamber.
An interior constriction placed at or near the muzzle end of a shotguns barrel to control shot dispersion.