Terms 3 Flashcards
Zone search
A crime scene search pattern in which a square or rectangular area is marked off and searched for evidence. A zone can be a room or, in outdoor scenes, a zoned-off area.
ABFO scale
A photographic scale designed by the American Board of Forensic Odontology that is used to ensure accurate depiction of injuries and other items of physical evidence.
Accessories
A classification of explosives that includes initiation materials or fuzing systems that may contain low or high explosives or combinations of both types of explosives.
Action
The mechanism of a firearm directly behind the barrel, by which a gun is loaded, locked, fired, unlocked, extracted and ejected.
Active infrared
A sensor that emits an infrared beam to a receiver, forming an invisible link that, when broken, acts as a trigger to the IED. These sensors act like an electronic version of the trip wire.
Active/time-delay systems
A type of switch that functions after a set time, as in time bombs.
Adipocere
A grayish-white waxy or soapy-like substance that forms in the fatty tissues of the body and is usually formed when a body is placed in a damp environment such as water, a cave, or in a grave.
Administration worksheet
A written record that is used to collect data relative to the basic organization of investigative activities conducted at the scene. Airborne IED
Algor mortis
The cooling of the body after death occurs.
Alpha particles
A form of ionizing radiation released by the radioactive decay of nuclear materials that have a very short range in air and a very low ability to penetrate other materials.
Alternate light source (ALS)
A forensic light source created when a high- intensity light is focused through a fiber optic cable using various filters.
Alternating current (AC)
Electric current that flows through a circuit in both directions with the change in direction occurring with a well-defined and specified frequency; household current.
Alveolar region
The section of the jawbones containing the tooth sockets.
American Society of Testing and Materials (ASTM)
The recognized organization that establishes protocols and standards for testing and examination, including for the forensic sciences.
Ammonium nitrate
An oxidizer used in the manufacturing of high explosives and as a fertilizer in agricultural uses.
Ammonium nitrate and fuel oil (ANFO)
A high explosive/blasting agent that consists of ammonium nitrate prills and fuel oil.
Ancillary effects
Secondary blast pressure effects that are a direct or indirect effect of an explosion, including reflection and earth and water shock.
Anti-disturbance
A victim-operated trigger that senses when objects or their wrappings are moved or disturbed, initiating a firing device. Sensitive mechanisms such as tilt and trembler switches may be used.
Anti-infrastructure
IED incidents primarily intended to damage or destroy physical infrastructure such as pipelines, communication towers, bridges, buildings, utility lines and/or facilities such as electrical transformers or water pump houses.
Antiarmor
IED incidents primarily intended to damage or destroy armored vehicles and/or to kill or wound individuals inside armored vehicles.
Antipersonnel
IED incidents primarily intended to kill, wound, or obstruct personnel.
Antipersonnel mines
Placed ordnance that are designed to produce injuries or death in personnel.
Antitank
Ordnance designed to be used against tanks or similar armored targets.
Antitank/antipersonnel mines
Placed ordnance which are larger than antipersonnel mines and are designed to destroy tanks and other armored and unarmored vehicles.
Antivehicle
IED incidents primarily intended to damage or destroy vehicles—excluding armored vehicles—and/or their cargo as well as to kill or wound individuals inside such vehicles.
Anvil
That part of the cartridge primer which is a solid surface, against which the firing pin strikes to set off the priming powder.
Arches
The fingerprint class characterized by ridge lines entering the print from one side and flowing or tending to flow out the other side. There are two types of arches—plain and tented. The friction ridges forming a plain arch form a wave pattern. The tented arch has a sharp upthrust or spike in the center that gives the impression of a tent.
Area of origin
In arson investigations, the location where the heat ignited the first fuel; it will also be the area with the most visible damage in the fire scene.
Armed device
An electrical, mechanical, or chemical fuzing system that is capable of functioning when acted on or disturbed by an unsuspecting victim
ASA/ISO
A standard (American and international) nomenclature for depicting a film’s ability to record light in terms of speed. The higher the ASA/ISO number, the less light it takes to record an image on film.
Attack geography
A description of the geography surrounding the IED incident, such as road segment, building, or foliage. Understanding the geography indicates the bombers use of landscape to channel tactical response, slow friendly movement, and prevent pursuit.
Autoloading
See Semi-AutoMatic
Autopsy
A medical procedure involving the internal and external examination of a dead body conducted by a pathologist or medical examiner to determine the cause and manner of a person’s death and to evaluate any disease or injury that may be found.
Bacteria
Single-celled organisms that multiply by cell division and that can cause disease in humans, animals, or plants. They include anthrax, cholera, plague, and tularemia.
Ball
The round lead missile fired by smoothbore firearms. (The term is used today when referring to some types of bullets fired from rifled barrels).
Ballistic Coefficient
A number which indicates how a bullet’s shape, length, weight, diameter and nose design affect its stability, velocity and range against air resistance.
Ballistics
The study of a projectile in motion.
Ballistics
The study of what happens to moving projectiles in the barrel and in flight - their trajectory, force, impact and penetration. ÒInternal ballisticsÓ refers to what happens inside the barrel before the bullet or shot leaves the muzzle; Òexternal ballisticsÓ is what happens after the bullet or shot leaves the barrel and travels to its final point of impact and Òterminal ballisticsÓ is what happens to the bullet at the final point of impact.
Band seat (rotating band seat/driving band seat)
Machined or cast groove around the circumference of a projectile into which the rotating band is seated.
Barrel
The metal tube of a firearm made from iron or steel, through which the bullet or shot charge passes when the firearm is fired.
Base Wad
The paper filler at the rear of the powder charge of the shotgun shell.
Baseline measures
A line of reference from which measurements are taken, usually a wall using 90-degree angles.
Battery
The metal arm of a flintlock mechanism, against which flint strikes to create sparks in the flashpan (also called the ÒfrizzenÓ).
Beavertail
A wide, flat fore-end of a rifle or shotgun.
Bedding
That part of the stock into which the barrel fits.
Belt
The narrow band around the rear section of a cartridge case just forward of the extractor groove. (The belt arrests the progress of the case into the chamber and controls headspace.)
Berdan Primer
See Primer
Beta par tides
A form of ionizing radiation released by the radioactive decay of nuclear materials that travel faster and are smaller than alpha particles and can be stopped by skin or clothing.
Binary chemical
A toxic chemical derived from the mixing of two relatively nontoxic constituents.
Binary explosive
A detonator-sensitive high explosive consisting of two substances, an oxidizer and a fuel, that when mixed together form an explosive.
Biohazard bags
Containers for materials that have been exposed to blood or other biological fluids. Gloves and other personal protective equipment worn at the crime scene by personnel should be collected in a biohazard bag that is then removed and disposed of properly by the agency conducting the investigation.
Biological fluids
Any fluids encountered that are thought to be of human or animal origin. The most common fluids are blood, saliva, semen, urine, or sweat. Any evidence suspected of containing biological fluids should have a biohazard label affixed to the package used to collect the evidence.
Biological warfare agents
Living organisms that are used to intentionally cause disease in or harm humans, animals, or plants.
Black Powder
A finely ground mixture of three basic ingredients - saltpetre (potassium nitrate), charcoal (carbon) and sulphur.
Black powder
A low-explosive mixture containing sulfur, charcoal, and potassium or sodium nitrate. It is the oldest known explosive.
Blast
In this context, a primary effect caused by the detonation of a high-explosive main charge constructed without a hard-cased container.
Blast fragmentation
An explosion effect achieved with either high or low explosives that may use a hard container or have fragmentation shrapnel added to or around the main charge explosive.
Blasting agents
High explosives that cannot be reliably initiated with a #8-strength detonator and require a booster to function.
Blister agents
Persistent chemical agents that produce severe burns and blister the skin or any other part of the body they contact; includes sulfur mustard, nitrogen mustard, lewisite, and phosgene oxime.
Blood agents
Chemical agents that interfere with or prevent oxygen utilization at the cellular level and include hydrogen cyanideand cyanogens chloride.
Bloodborne pathogens
Infectious disease-causing microorganisms that may be found or transported in biological fluids.
Bloodstain pattern analysis (BPA)
The examination of the shapes, locations, and distribution patterns of bloodstains, in order to provide an interpretation of the physical events that occurred at the crime scene.
Blown Pattern
A shotgun pattern with erratic shot distribution, generally caused by gas escaping past the wads and getting into the shot.
Bluing
A process of treating metal gun parts in a bath of metallic salts and water, which colors them blue to prevent rust.
Boattail
The tapered rear end of a bullet. (Also called Òtaper heel”, this design is used to increase ballistic efficiency at long range.)
Body
The external container of military ordnance, which can serve the dual purpose of being an external protecting container and may provide for fragmentation.
Boiling-liquid expanding -vapor explosion (BLEVE)
An example of a mechanical explosion involving containers that contain liquids under pressure that are heated by an exterior heat source, which causes the container to rupture. Frequently seen when a gas cylinder, tank, or rail cars are involved in fires.
Bolt
A steel rod-like assembly which moves back and forth in a bolt action, sealing the cartridge in the chamber during firing.
Bolt Face
The forward end of the bolt which supports the base of the cartridge and contains the firing pin.
Bomb
In a broad sense, an explosive or other lethal agent, together with its container or holder, which is planted or thrown by hand, dropped from aircraft, or projected by some other slow-speed device (as by lobbing it from a mortar). Military bombs/dropped ordnance a re of two types
Bomber’s signature
An identifiable pattern or characteristic of using essentially the same or similar bomb construction components and construction, fabrication and design/alteration techniques in multiple devices by the same person or persons who have access to those components and design/alteration techniques.
Bombing crime scene
The physical location where an IED has exploded or where such a device has been recorded or dismanded bv bomb technicians.
Booster
In commercial blasting,a detonator-sensitive, high-energy, high explosive charge used to initiate a main-charge explosive that is incapable of being initiated with only a detonator.
Bore
The tunnel down the barrel of a firearm through which the projectiles travel.
Bore Diameter
The measurement from one side of the bore to the other. In a rifled barrel this means measurement of the bore before the rifling grooves are cut.
Breech
The rear end of the barrel (in modern arms, the portion of the barrel into which the cartridge is inserted. See Chamber.
Breechblock
The part in the breech mechanism that locks the action against the firing of the cartridge.
Breechloader
A firearm loaded through the breech.
Brisance
The shattering effect of an explosive.
Buckshot
Large lead pellets used in shotshells.
Bulk military explosives
Military explosive in its original packaging or that has been removed from weapons or munitions.
Bullet
A single projectile fired from a firearm.
Bullet sale explosive
Explosives that cannot be detonated by a 150-grain ball bullet having a nominal muzzle velocity of 2700 ft/s as fired from a caliber .30 rifle at a distance of 100 ft when the test material is placed against a 1/2-in-thick steel plate at a temperature of 70° F-75°F.
Burn patterns
Visible effects from a fire, such as charring, smoke, and soot deposits; changes in the character of materials; and the consumption of consumables that may indicate the ignition source of a fire.
Butt
The rear end of a rifle or shotgun. (The portion that rests against the shoulder.)
Buttplate
A plate which covers the butt. (Some steel buttplates have trap doors covering a recess for storage of cleaning equipment.)
C\ clotiimethyleneti initi amine (RDX)
A detonator-sensitive high explosive that is used in detonators, detonating cords, and in demolition explosives when combined with a plasticizer.
Cache
An IED incident that involves the discovery and/or recovery of unarmed devices, IED components, and IED paraphernalia that involves long-term storage in a permanent, fixed location.
Cadaveric spasm
The rapid stiffening of the hand that sometimes occurs at the time of death.
Calibre
The diameter of the bore of a rifle before the rifling grooves are cut.
Cannelure
A groove around the circumference of a bullet or case. (For example, the lubrication grooves of lead bullets, or the grooves into which the mouth of the cartridge case is crimped, or the extractor grooves of the rimless or belted case.)
Cant
To tilt or lean a gun to the side when aiming.
Cap
See Percussion Cap.
Carbine
A light short-barreled riffle.
Cartridge
A case, usually made of brass or copper, containing the powder charge, the primer and the bullet. (Before development of the metallic cartridge, the term was used to mean a roll or case of paper containing powder and shot. Modern cartridges are generally classified in three categories Ñ Òcentrefire metallicsÓ, rimfiresÓ and ÒshotshellsÓ. Centrefire metallics include all metal cartridges that have primers in the center of the base. Rimfires include all cartridges in which the priming powder is sealed in the soft rim around the base. Shotshells include all cartridges that contain shot, or small pellets, instead of a single bullet.)
Case file
A compilation of all case documents pertaining to an investigation, including evidence and photography logs, photographs, sketches, case narrative, laboratory requests and reports, and other records.
Case narrative
A running description of the entire crime scene investigation that should be presented in the same systematic, methodical, and logical manner in which the activities were conducted at the scene.
Cast explosive
An explosive that is heated to a liquid state, poured into a mold /container, and allowed to harden.
Cast-off patterns
Bloodstain patterns created when blood is released or thrown from a blood-bearing object in motion, such as a baseball bat or a pipe.
Cause of death (COD)
The reason a person ceased to live, whether by injury or disease; must be determined by the medical examiner during the autopsy
CBC (cyanoacrylate blowing contraption)
A fuming device developed by Arthur M. Bohanon of the Knoxville (Tennessee) Police Department in the early 1990s. It is specifically designed to detect latent fingerprints on dead human bodies.
CBRNE
A common acronym used when discussing weapons of mass destruction; the letters represent chemical, biological, radiological, nuclear, or explosive agents.
Centre-Fire
See Cartridge.
Chain of custody
The proper documentation showing each change in possession and/or storage of an item of evidence from its seizure to trial presentation.
Chamber
The enlarged portion of the barrel at the breech in which the cartridge is placed ready for firing.
Chapman- Jourget (CJ) plane
Regarding the combustion of an energetic material, the end of the reaction zone or where the burning of the energetic material stops and the stable products of the reaction begin.
Checkering
A diamond-like patter on fore-ends and grips of firearms. (The diamonds are made by cutting crossing lines into the material with special tools.)
Chemical agents
Any solids, liquids, or gases that produce lethal, injurious, or irritant effects resulting in casualties.
Chemical compound
A combination of two or more materials to form a new material wherein the constituents are chemically combined and lose their original identities.
Chemical explosion
An explosion caused by rapid conversion of a solid, liquid, or gas into gases having a much greater volume than the substances from which they were generated.
Chemical fuzing systems
A timing switch using the reaction of chemical compounds as a switch to provide a delay before starting the initiation train.
Choke
The constriction at the muzzle of a shotgun barrel by which the spread of the shot pattern is controlled.
Choking agents
Casualty-producing agents that cause irritation and inflammation of the bronchial tubes and lungs from inhalation. They cause pulmonary edema, which fills the lungs with liquid, choking the victim. They include chlorine and phosgene.
Chop shop
A structure or location used for receiving, dismantling, destroying, or concealing passenger motor vehicles or parts that were illegally obtained.
Circumstantial indicator
A sign or indicator that relies on the circumstances of a particular situation or may be incidental to an attack and can include unusual activities around the target or the significant timing of an incident.
Claymore effect
An explosives charge configuration, military or homemade, designed to explosively propel a fan-shaped pattern of ball bearings or other fragmentation in an aimed direction.
Closed device
An IED in which the components are hidden from view by the use of an external container.
Cock
To set the action into position for firing. (On some firearms the action has an intermediate position called half cock. On early weapons such as the flintlock and percussion cap, the hammer was called a cock.)
CODIS (Combined DNA Index System)
A database maintained by the FBI as a central repository for DNA profiles. CODIS allows law enforcement agencies and state crime labs to exchange and match DNA profiles electronically. It contains a Forensic Index of profiles from crime scene evidence and an Offender Index composed of profiles of subjects convicted of violent crimes and sex offenses.
Color coding
A system of ammunition identification by color, wherein each item of ammunition is painted with a color or combination of colors in accordance with a code to make for ready identification, particularly when out of its original container. Color codes have changed many times over the years and vary widely, in some cases, from country to country. Selected markings on ordnance may also be color coded to aid in identification.
Comb
The upper edge of a rifle or shotgun stock where the cheek rests.
Combination device
An IED wherein the components are partially hidden from view.
Command fuzing system
A type of switch that is activated by the attacker in which the attacker controls the device at the moment of initiation. They include radio/wireless transmitters or receivers, continuous lengths of electrical wire, or continuous lengths of wire, rope, or string extending from a remote location to the IED that when physically pulled or manipulated cause the fuzing system to initiate.
Command projectile
The use of a small-arms bullet to close the circuit by penetrating two metal plates. This provides a standoff between firing point and contact point.
Command-pull IED
An IED initiated by a person using a “command-pull” action.
Command-wire IED
An IED in which the firing point and contact point are separate but joined together by a length of wire.
Commercial explosives
Explosives available for purchase on the open market for commercial purposes.
Comparison samples
Physical evidence from the crime scene that can be compared with samples from suspects, victims, and known standards.
Composition B explosive
An explosive usually composed of 59.5% RDX, 39.5% TNT, and 1% wax. Usually, an explosive used by the military.
Composition C explosive
An explosive normally consisting of RDX, a plasticizer, and a binder. The original Composition C was used by the British during World War II as a plastic demolition charge. As standardized in the Unites States, it has had modifications resulting in Composition C2, C3, and currently, Composition C4. C4 is used as a filler in some military ordnance and as a demolition charge.
Compression toolmarks
Toolmark impressions that are created when a tool is pressed into a softer material, usually showing the outline of the tool used to create the impression.
Computer crime
A term describing a myriad group of offenses defined by state and federal statutes and including activities such as unauthorized access, software piracy, alteration or theft of electronically stored information, transmission of destructive viruses or commands, and child pornography and predatory activities.
Concentric fractures
A glass fracture pattern consisting of a series of circular cracks that surround the impact site and move away from the site, with each circular fracture increasing as it propagates outward.
Cone
The sloping portion at the front end of a shotgun chamber in which the chamber diameter is decreased to the diameter of the muzzle. Also, the rear portion of the choke at the muzzle of a shotgun.
Confirmatory test
A separate test that is conducted in the laboratory on a sample to confirm the identity of a substance or (in the case of body fluids) an individual.
Conical Bullet
A cone-shaped bullet.
Conical charge
A shaped charge having a cavity in the shape of a cone, which is fashioned to provide an enhanced explosive effect, also known as the Munroe effect.
Contact stains
In bloodstain pattern analysis, stains created when a bloody object comes into direct contact with a surface, for example, bloody fingerprints found on a countertop.
Container
An external covering that can be used for concealment, means of transporting, or for containment of the main charge.
Control or blank sample
Material from a verifiable source that is uncontaminated; a good example is when a segment of unaffected carpet is removed from the scene of a suspected arson that does not appear to have been affected with an accelerant.
Cordite
A double-base smokeless powder made of nitroglycerine and guncotton which is used in the form of long, stringy cords.
Core
The part of a bullet that is covered by a jacket.
Coroner
An elected or appointed official whose duty it is to investigate deaths that occur within jurisdictional limits. Responsibilities of coroners vary depending on the statutory requirements of the individual county or state.
Corpus delicti
The determination of the essential facts that demonstrate that a crime has occurred.
Corrosion
The gradual eating away of the metal parts of a firearm caused by rust.
Corrosive
A chemical timing switch using a corrosive chemical with a known decomposition rate that is designed to destroy a physical restraint on a triggering device to start the initiation train.
Creep
The movement of the trigger before it releases. (Also called drag or crawl.)
Crime scene investigation
An overall investigation conducted at the crime scene to locate and identify evidence left behind, taken away, or altered in some way that will aid in the solution, arrest, and convictions of the persons responsible.
Crime scene investigator
Specially trained personnel assigned to process locations where crimes have been committed. CSIs may be sworn police officers or civilian personnel.
Crime scene photography
A systematic depiction of the pertinent features of the scene as seen through the lens of a camera.
Crime scene reconstruction
The systematic process of piecing together information and evidence in an investigation to gain a better understanding of what occurred between the victim and the offender during the commission of a crime. The crime scene reconstructionist uses physical evidence and information to infer what occurred during the interaction between the offender and the victim.
Crime scene search
A collection of physical evidence that will reconstruct the crime and identify and link the subject or subjects to that crime scene.
Crime scene staging
In cybercrime investigations, when the perpetrator attempts to plant or fabricate digital evidence that will implicate another individual.
Crimp
The portion of a cartridge case that is bent inward to hold the bullet in place, or in the case of shotshell, to hold the shot charge in place.
Cross Hairs
The sighting lines in a telescopic sight.
Cross-contamination
The transfer of material between two or more sources of physical evidence.
Cross-sectional plans
Two-dimensional drawings most easily described as cutaways of the exteriors of elevations; they reveal the interior, floors, and subterranean levels of buildings or structures.
CSI effect
The recent phenomenon that takes place when the real-world expectations of crime victims and jury members, which are based on unrealistic television and film portrayals, pressure prosecutors to deliver more forensic evidence than usual in court or explain why they cannot do so.
Cup
A detachable metal case designed to hold a number of cartridges for loading into the firearm.
Cutting toolmarks
Marks created by tools such as bolt cutters or tin snips and usually found on chains and hasp locks that have been cut through.
Cyberbullying
The use of the Internet to send or post text or images intended to hurt or embarrass another person.
Cybercrime
Technology-assisted crimes that generally involve the use of the Internet.
Cyberstalking
The pursuit and harassment of victims through use of the Internet.
Cybertailing
The actions of tracking a cybercrime perpetrator through various computer networks to identify a suspect.
Daisy chain
A single IED with one firing signal that can initiate multiple connected main charges.
Damascus Barrels
Barrels made of strips of iron and steel welded together in a spiral fashion. (Modern ammunition should not be used in such firearms.)
Date-plant-shift code
A federally mandated requirement for accountability, which requires all commercially manufactured packaged high explosives to have a tracing code on each package manufactured that indicates the date, manufacturing facility, shift, and batch or run of the explosive.
Daubertrulings
Court rulings that established that human friction ridges are unique and permanent. TheDaubertrulings clarified the scientific acceptance of the uniqueness of friction ridges in court proceedings.
Defensive wounds
Wounds that occur as the victim is attempting to ward off an attack; typically on upper or lower extremities and are of lesser severity than those elsewhere.
Deflagration
Energetic materials, usually low explosives, that decompose at a rate below the speed of sound in that product; rapid burning.
Dental stone
A casting medium composed of calcium sulfate (plaster of Paris) with potassium sulfate added for greater hardness. It is generally preferred over plaster of Paris because it is harder and less brittle.
Detection precursor
A material placed into high-energy plastic explosives to aid in its detection prior to detonation.
Deterrent
A material added to an explosive to slow its burning rate.
Deterrents
A category of chemicals that are added to smokeless powder used to control and reduce the burning rate of the powder by coating the exterior of the granules or being absorbed into the powder.
Detlagration-to-detonation transition
A characteristic of primary explosives whereby the explosive is initiated by heat or flame and deflagrates, but then transitions to a detonation.
Detonating cord (Detcord/Primacord)
A flexible cord containing a central core of high explosives used to initiate high explosives along its length.
Detonation
The instantaneous combustion of an energetic material at a rate of faster than the speed of sound in that product.
Detonator
A cylindrically shaped capsule, normally made of aluminum, copper, or gilding metal, containing at least a primary and a secondary high explosive used to initiate high explosives.
DFO
1,8-Diazafluoren-9-one, a chemical that reacts to amino acids and is effective in visualizing latent fingerprints on porous materials.
Diagramming (crime scene)
A visual representation of a scene through the use of drawing or sketching that provides details not possible with written documentation or photographs.
Diazodinitrophenol (DDNP)
A primary high explosive used in initiation systems and detonators to initiate secondary explosives.
Digital evidence
Data stored or transmitted using a computer that is probative in nature and can be used to generate investigative leads
Digital forensics
The extraction and analysis of digital evidence from computers.
Direct current (DC)
Electric current that flows through a circuit in just one direction; battery power.
Direct marking
For establishing a chain of custody and the individual identity of evidence, the method of marking onto the item of evidence.
Directionality
The directionality of a bloodstain or pattern that indicates the direction the blood was traveling when it impacted a surface. The geometric shape of a bloodstain can usually establish the directionality of a flight of a blood drop.
Dispenser bomb
An item designed to be mounted, but not permanently fixed, on aircraft to carry and eject small ordnance or submunitions. Some dispensers remain on the aircraft after dispersing their cargo, while others are released from the aircraft and disperse their cargo during the drop phase.
Domain Name System (DNS)
A hierarchical naming system for computers, services, or any resource connected to the Internet or a private network, which associates various information with domain names assigned to each of the participants.
Double-Base Powder
A rapidly burning powder made by absorbing nitroglycerine into nitrocellulose (guncotton). (Cordite is a double-base powder.)
Doughnut Pattern
A shotgun pattern with a hole in the middle generally caused by the interference of the top wad.
Down Range
The direction from the shooting position to the target on a range. See Range.
Drift
The departure of a bullet or shot charge from the normal line of flight. (This can be caused by wind or the unbalanced spinning of the bullet.)
Drilling
A three-barrel gun with a rifle barrel beneath two shotgun barrels. (Generally of German manufacture.)
Driver’s point of view
The view of the driver of a vehicle through all windows at the time a vehicle was being operated. This is a useful documentation point that may be used to identify or eliminate obstructions or causative factors of a motor vehicle crash.
Driving band
See Rotating band.
Driving band seat
See Band seat.
Dropped ordnance
A broad category of military ordnance that is intentionally dropped or released from an aircraft and can include bombs, dispensers, flares, and submunitions.
drown ordnance
Ordnance commonly known as hand grenades, classified as antipersonnel, antitank, smoke, and miscellaneous.
Dud/dud fired
An explosive munition that has not armed or that has failed to function as intended after arming has taken place.
Dyes
Coloring agents that dye smokeless powder for identification purposes.
Dynamite
A general term given to a class of detonator-sensitive high explosives in which the principal energetic material is usually nitroglycerin and/or ethylene glycol dinitrate (EGDN).
EDTA
Ethylenediaminetetraacetic acid, an anticoagulant and preservative added to test tubes used for the collection of liquid blood samples. EDTA tubes are usually equipped with lavender-colored rubber tops for easy identification.
Ejector
The mechanism which throws the cartridge case free from the gun.
Electric detonator
Detonators that are initiated through electrical energy.
Electric matches
A pyrotechnic firing device that burns with an external flash, used to initiate low explosives, primary explosives, and shock tubes.
Electrical explosion
The result of high-energy electrical arc, which generates sufficient heat to cause the failure of the containing component.
Electrical fuzing system
IED initiation system that uses electrical energy, AC or DC, to initiate the initiator.
Electrical switch
A mechanism used in the fuzing system of an IED to provide or allow for electrical energy to flow from the power source to the initiator in order to initiate the device.
Electronic signature
A symbol, sound, or process attached to or logically associated with a record, and executed or adopted by a person with the intent to sign the record.
Electrostatic dust print lifter
A device that utilizes an electrical charge applied to a metallized lifting mat that will attract positively charged dust particles; this results in a mirror image of impressions made by footwear or tires.
Elevation
The degree of adjustment of a rear sight or scope reticule necessary to cause the bullet to strike higher on the target.
Elevation plans
Two-dimensional, side-view representations of the walls, sides of furniture, cabinetry, and fixtures of an interior scene.
Elimination samples
Samples taken from individuals who have had legal access to a crime scene that will be used as a comparison with evidence collected from the scene.
Emulsitier
An ingredient that binds or holds the fuel and oxidizer together in an emulsion explosive.
Encryption
The process of converting readable digital objects (plain text) into unreadable digital objects (ciphertext) using a mathematical function.
Energetic material
Any material capable of undergoing rapid decomposition.
Energy
The amount of work done by a bullet, expressed in foot pounds.
Enhancements
An optional additional component deliberately added, as opposed to a secondary hazard that modifies the effects of the IED. The IED would be effective, yet produce a different measurable result if this effect was not added. This effect can be additional physical destruction, proliferation of dangerous substances (i.e., radiation, chemicals), or other effects to enhance the outcome of the IED.
Entomology
The branch of science that deals with the study of insects.
Epicenter
The area or point within the scene that has the greatest concentration of damage.
Erosion
The wearing away of a barrelÕs metal surface by a bullet or shot charge or by the heat of powder gases.
ESDA (electrostatic detection apparatus)
A device that examines paper for indentations and other latent impressions.
Evidence dynamics
Influences that may change, relocate, obscure, or obliterate evidence, regardless of whether intent existed, between the time evidence is transferred from the crime scene and the time the case is resolved. If these changes occur, it makes it more difficult for the prosecution to prove the authenticity and reliability of the evidence.
Evidence recovery log
A written record used to record or document the collection of evidence, it is the first step in establishing a chain of custody.
Exemplars
In handwriting analysis, standards of known handwriting used for comparison purposes.
Exploding bridge wire
A term used to describe an initiator or system in which a very high-energy electrical impulse is passed through a bridge wire, literally exploding the bridge wire and releasing thermal and shock energy capable of initiating a relatively insensitive explosive in contact with the bridge wire.
Explosion scene
The physical location where an explosion of undetermined origin or circumstances has occurred.
Explosive
Any chemical compound or mixture (energetic material) whose purpose is to function by explosion.
Explosive ordnance
Term used to denote ordnance material that normally contains explosives. Examples include projectiles, grenades, bombs, torpedoes, depth charges, rockets, small-arms ammunition, mines, and missiles.
Explosive performance
Refers to how well an explosive explodes, or conversely, how well it does not explode, for example, low/high order.
Explosive sensitivity
The amount of stimulus (heat, shock, friction, static electricity) required to initiate the chemical reaction in the energetic material.
Explosive-Incendiary
A device that has an explosive effect in combination with an added combustible material, such as gasoline.
Explosively termed projectile (EFP)
Specially designed main-charge configuration incorporating an explosive charge with a machined or pressed concave metal plate by which the force of the charge reshapes the plate into a high temperature, high-velocity metal slug capable of penetrating armored vehicles.
Extractor
A hook device which pulls the case out of a chamber as the breech mechanism is opened. (The extractor generally brings the case within reach of the ejector, which then flips it out of the gun.)
f.p.s.
Abbreviation for feet per second. A term used in expressing the velocity of a bullet.
Fastener
Refers to a wideassortment ofsheet metal and wood screws,bolts, nuts, washers, and so on, that are used in the construction of an IED.
Feed
The action of moving live cartridges from the magazine of a firearm into the chamber.
Femur
The largest and strongest bone in the body, which extends from the pelvis to the knee.
Field investigation
The investigation conducted away from the location of the incident or crime scene.
Filler
The type of payload (main charge) in military ordnance; can be explosive, chemical, nuclear, biological, or leaflets.
Find
An IED incident involving the discovery, recovery, or turn in of unarmed devices or IED components that also involves short-term storage in a temporary and/or transitory location.
Fire triangle
The three components necessary for a fire to burn
Firing Pin
The part of the breech mechanism which strikes the primer of the cartridge. (In most firearms, the firing pin is part of the bolt assembly.)
Fixed munitions
Ammunition in which the cartridge case is permanently attached to the projectile.
Flash suppressants
A category of chemicals that are added to smokeless powder primarily used in military triple-base powder to reduce the flash from the end of the gun barrel.
Flinch
To move or jerk a firearm involuntarily while shooting.
Flint
A piece of stone held in the cock of a firearm. (When it strikes the steel battery, or ÒfrizzenÓ, this causes a shower of sparks to fall into the flashpan and ignite the powder.)
Flintlock
The gunlock of early firearms in which flint is thrown against steel, causing sparks to ignite the powder charge.
Floor plans
Two-dimensional, “bird’s-eye” views of a room or a series of rooms that make up a floor of a structure or building.
Floor Plate
The detachable metal plat at the bottom of the cartridge magazine of a bolt action rifle. (The floor plate is usually hinged at the front and held by a release spring located just ahead of the trigger guard.)
Fore-End
The forward portion of a shoulder-arm stock. (Located under the barrel, the fore-end serves as a hand-hold.)
Forensic anthropologist
A practitioner in the branch of physical anthropology that deals with the identification of skeletonized human remains.
Forensic biology
The study of life, including both cellular and molecular biology. This is essential to the scientific analyses required in crime laboratories.
Forensic entomology
The field in which arthropod science and the judicial system interact.
Forensic linguistics
The field of forensic science that uses phrases, word usage, punctuation, letter forms, and number forms to determine the personality and/or type of the writer of a document.
Forensic nurse
A medical professional who has received training in the medicolegal aspects that encompass treatment and physical evidence identification in treatment facilities.
Forensic scientist
An individual trained as a biologist or chemist and skilled in the protocols of scientific analysis in the laboratory setting.
Fragmentation
High-speed missiles that are a result of an explosion and may be a part of the explosive casing, container, earth, building material, target area or other items affected by the explosion.
Frizzen
See Battery.
Fulminate Of Mercury
A highly sensitive explosive used as a primer compound.
Fuse caps
Nonelectrical detonators that are initiated with safety fuse.
Fuse lighter
An enclosed pyrotechnic device used to initiate or light safety fuse.
Fuze (military fuzing system)
A device with explosive or nonexplosive components designed to initiate a train of fire or detonation in ordnance by an action such as hydrostatic pressure, electrical energy, chemical, impact, mechanical, time, acceleration, deceleration, piezoelectric action, or a combination of these.
Fuzing system
A combination of components that when placed into operation provides the required stimulus to initiate the main charge explosive in an IED. Examples include electrical wire, switch, battery and electrical detonator; safety fuse, nonelectrical detonator, and fuse lighter.
Gain Twist
Barrel rifling which increases in pitch from the breech to the muzzle to accelerate the spin of a bullet.
Gamma rays
High-energy protons emitted from the nucleus of decaying atoms that are similar to X-rays. They can penetrate deeply into a body and are the most lethal form of radioactive energy.
Gas Check
A metal cup placed on the end of a lead bullet to protect the lead against the hot gases of the burning powder charge.
Gas chromatography
An instrument in the crime laboratory that is used to analyze and identify suspect samples. The samples are separated during the analysis and often the gas chromatograph is linked to the mass spectrometer, which provides positive identification.
Gas Port
A small hole in the barrel of a gas-operated firearm through which expanding gases escape to power the autoloading system.
Gauge
Measurement of shotgun bores derived from the number of bore-sized balls of lead to the pound. For example, 12 balls which fit the bore of a 12-gauge shotgun weigh one pound.
Gentian violet
A staining solution that is used to process adhesive tape for latent fingerprints.
Global adjustments
In photography, gross adjustments that affect the entire world within the image, equally affecting the entire photograph (e.g., orientation, brightness, contrast).
GPS
Global positioning system, a system based on 24 satellites that circle the earth providing accurate longitude, latitude, and altitude positions to GPS receivers on earth.
Graphite
A material added to low explosives, referred to as glazing, in order to improve the flow of the powder, improve packing, and to reduce static electricity buildup when the powder is poured.
Graphology
The field of psychology that attempts to profile the personality of an individual based on his or her handwriting characteristics.
Grenade
A weapon, military or homemade, designed to explode when a restraint is removed (usually handheld, but can be projected).
Grid search
A crime scene search pattern in which a strip search is made in one direction then repeated over the same area in a right angle; also known as the double-strip search method.
Grip
The small portion of the stock gripped by the trigger hand.
Grip Cap
A cap fastened over the end of a pistol grip on a rifle or shotgun stock.
Grooves
See Rifling.
Group
A series of shots fired with the same sight setting and the same aim.
Guided missile
An unmanned vehicle designed to be propelled above the surface of the earth on a trajectory or flight path capable of being altered by an external or internal mechanism.
Gunshot residue (GSR)
A substance expended from the barrel of a weapon when it is discharged; composed of gunpowder residue and soot.
Hackers
Internet crime perpetrators who attempt to break into networks in order to gain access to secure information or use to commit other offenses.
Half Cock
See Cock.
Half-lite
The time required for the activity of a given radioactive species to decrease to half its initial value due to radioactive decay.
Hammer
The part of the action that drives the firing pin forward.
Hammerless
Refers to a firearm whose hammer and striker are concealed within the metal frame.
Hand Cannon
On a variety of small, crude cannons used in the early 15th century.
Handwriting complexity
Generally the number of complex moves necessary to create a signature or handwriting consisting of curves, loops, and embellishments.
Hangfire
Delay in firing a cartridge after the firing pin has struck the primer.
Headspace
The distance between the base of the cartridge and the face of the bolt or breechlock. (This is determined by the rim of rimmed cartridges, the belt of belted cartridges and the shoulder or rimless cartridges).
Heel
The rear end of the upper edge of a gunstock. Also the base of a bullet.
High explosives
Substances that explode at a detonation velocity faster than the speed of sound through that material (above 3,300 feet per second). High explosives do not need to be confined to function.
High explosives
Energetic materials that support a detonation wave, irrespective of the ambient condition of confinement.
High Intensity
Refers to cartridges having velocities of 2,700 per second (822.96 metres per second) or more.
High order
An explosive that undergoes complete burning or initiation of the material at its maximum velocity.
High Power
A term applied to the first smokeless powder cartridges with velocities of approximately 2,000 feet per second (609.6 metres per second).
Hobby/cannon fuse
A cord-like burning medium used to initiate low explosives, such as fireworks, which burns externally and consumes itself in burning.
Holding
The action of keeping the sights on the target while applying pressure to the trigger.
Hollow Point
A bullet with a nose cavity designed to increase its expansion on impact.
Homemade explosive (HME)
A combination of commercially available ingredients combined to create an explosive substance or a combination of military and/or commercial explosives in bulk and/or trace amounts that results in a new, nonstandard explosive mixture.
Humerus
The long bone of the arm, which extends from the shoulder to the elbow.
Identity theft
Crime that occurs when a perpetrator pretends to be another person for the purpose of committing fraud.
IEDs
Improvised explosive devices.
Igniting Charge
The charge used to ignite the propelling charge. (See Primer).
Impact fuze
A fuze in which detonation is initiated by the force of impact and that usually functions instantaneously or after a short delay. With rocket or projectile fuzes the term “point detonating” (PD) is often used.
Impact spatter
Bloodstains that are smaller than a freely forming drop.
Impression evidence
Marks or imprints that are created when one object comes into contact with a second item resulting in characteristics of the first object being left on the surface of the second. A good example is a shoe print left in a muddy driveway.
Improvised explosive device (IED)
Any combination of items or components that are neither designed nor produced to be used in conjunction with each other and, when placed together, constitute a mechanism that has the capability of exploding and causing personal injuries and property damage.
Incapacitating agents
Chemical agents that produce temporary physiological or mental effects, or both, which will render individuals incapable of concerting effort in the performance of their assigned duties. Examples of these agents include tear gas (riot control) and central nervous system depressants and stimulants.
Incendiary
A device that is designed to burn.
Incendiary materials
Any flammable or combustible material that is capable of burning.
Incendiary/thermal effect
The heat produced from the explosion or decomposition of an energetic material.
Incident geometry
A description of how the IED system was emplaced, including the angle of the device, the distance to target, line of sight (if necessary), and so on.
IND
1,2-Indanedione, which is used in conjunction with an alternate light source to visualize latent fingerprints on nonporous surfaces.
Indirect marking
For establishing a chain of custody and individual identity of evidence, the method of marking the evidence container or a tag attached to an item of evidence.
Inert
The descriptive condition of ordnance, or components thereof, which contains no explosive, pyrotechnic, or chemical agents.
Inertia Firing Pin
A firing pin which moves freely forward and backward in the breechblock. (The striker impels it forward while the explosion of the primer impels it backward).
Initial walkthrough/ preliminary assessment
The initial review of the crime scene by the CSI and lead detective to determine the strategy and define the scope of the crime scene investigation.
Inked impressions
Fingerprints that are generated when ink is applied to the friction ridges and the fingers are “rolled” side to side in an orderly manner on a 10-print card.
Integrated Automated Fingerprint Identification System (IAFIS)
The digitized computer database of fingerprints maintained by the FBI.
International Ballistics
See Ballistics.
Internet
A global computer network of interconnected smaller computer networks that are linked and enable information sharing via common communication protocols.
Internet protocol (IP)
A dynamic numeric locator assigned to a computer by an Internet service provider. The IP address consists of four sets of numbers, and each set contains digits ranging from 0 to 255. Example
Internet service providers (ISPs)
Commercial companies (such as AOL, Yahoo!, and Earthlink) that make the Internet accessible to the public by maintaining thousands of servers.
Iron Pyrites
See Pyrites, Flint.
Jacket
The outer covering over the inner metal core of a bullet.
Jaws
The vise-like device on a flintlock hammer used to hold the flint.
Jump
The amount of change in the bore axis, measured both vertically and horizontally, while the projectile moves from the chamber to the muzzle when it is fired.
Kentucky Rifle
A flintlock rifle with a long barrel and short, crooked stock.
Keyholing
The failure of a bullet to remain balanced in flight so that it enters the target sideways, leaving an elongated opening.
Keying
A method used for attachment of projectile rotating bands.
Kick
The backward movement of a firearm generated by the discharge of the projectile. See Recoil.
Known samples
Materials from an identified or known source that are provided to the crime laboratory for comparison to unknown or questioned samples.
Knurl
To roughen or indent the surface, usually a pattern, such as on the exterior of a removable cap. As found on artillery projectiles, the raised knurls help hold the rotating band in place and keep it from slipping as the projectile moves down the rifling barrel.
Knurled Surface
A metal surface which contains a pattern of ridges or beads. (This rough surface aids grasping a metal part to move it.)
L.R.
Abbreviation for long rifle.
Lands
In the rifling of a bore, the uncut portions of the barrelÕs inner surface left after the rifling grooves have been cut into the metal. See Rifling.
Lands and grooves
Ridges ground inside the barrel of a gun in order to make a bullet travel straight. The original surfaces of the barrel are referred to as lands (or hills), and the newly created ridges are called grooves (or valleys), and they twist down the length of a gun to improve accuracy.
Large vehicle borne IED (LVIED)
An IED buik into any large ground-based vehicle (e.g., dump truck, panel truck, bongo truck, commercial bus, tanker) and for that serves as the concealment means for a large amount of explosives.
Laser protractor kit
A specially designed zero-based laser protractor that is used for determining trajectories.
Lead azide
A primary high explosive used in initiation systems and detonators to initiate secondary explosives.
Lead styphnate
A primary high explosive used in initiation systems and detonators to initiate secondary explosives.
Leading
Fouling of a firearm bore by metal particles from bullets adhering to the metal surface caused by heat or friction.
Lede
The bevelled portion of the rifling at the rear end of the barrel (and the forward portion of the chamber) where the bullet first engages the lands.
Legend
A note on a map or crime scene sketch that explains specific information of interest; may also contain the definition of symbols used on the sketch or map.
Length Of Pull
The distance from the front trigger of a shotgun to the centre of the butt.
Lethal dose
The amount of ionizing radiation exposure required to cause death.
Letter of transmittal
A communication or letter from the contributor of evidence used to request laboratory examination of evidence recovered at a scene.
Lever Action
An action operated by a lever located underneath it. (A secondary purpose of the lever is to serve as a trigger guard.)
Light bulbs/flash bulbs
Devices used as electric initiators that incorporate an improvised use of the bulb to initiate primary or low explosives.
Light sensitive
A type of proximity trigger that senses changes in the amount of light in the environment near the sensor. When this happens, the sensor causes a circuit to be completed, firing the device.
Line Of Bore
An imaginary straight line through the centre of the bore of a firearm extending to infinity.
Line Of Sight
An imaginary straight line from the eye through the sights of a firearm to the target.
Line quality
The level of skill, including the complexity, of handwriting.
Linear charge
A shaped charge having two intersecting flat planes used to concentrate the explosive forces.
Link search
A crime scene search technique that uses logical associations among the victim, suspect, and physical evidence to locate physical evidence.
Livor mortis
Lividity that appears when blood stops circulating and sinks to the lowest portions of the body.
Load
A charge of powder, a projectile or a cartridge. Also, to prepare a gun for firing by inserting ammunition into it.
Loading Gate
The hinged cover over the opening through which cartridges are inserted into the magazine.
Locard’s theory of exchange
A theory that maintains that transfer of evidence will occur between a suspect and victim and a location whenever contact occurs; also known as Locard’s exchange principle.
Lock
The firing mechanism of a a muzzle-loading weapon. In breech-loading firearms, the lock is the firing mechanism and breech-sealing assembly.
Lock Time
The interval of time between trigger release and the detonation of the primer. (Also called lock speed.)
Locking Lugs
A series of projections on the bolt of a firearm designed to fit into corresponding slots in the receiver to lock the action in closed position for firing.
Lockplate
A metal plate on which the firing mechanism is mounted on percussion and earlier firearms.
Loops
The fingerprint class characterized by ridge lines that enter from one side of the pattern and curve around to exit from the same side of the pattern. All loops have one delta, and the center of the pattern area is the core. If the loop opens toward the little finger, it is an ulnar loop (the ulna bone is the small bone on the outside of the forearm). If the loop opens toward the thumb, it is called a radial loop (the radial bone is the larger, inner bone of the forearm).
Lot numbers
An accountability system used for military-manufactured explosives, much like the date-plant-shift code; also known as the production code.
Low explosives
Explosives in which components burn rather than explode; they are propellants that travel at speeds of less than 3,300 feet per second. Black powder is the most common type of low explosive, and it is used to make safety fuses. Smokeless powder is another type of low explosive and is found in small arms ammunition.
Low explosives
Energetic materials that function by deflagration and under any conditions cannot support a detonation wave.
Low order
An explosive that undergoes incomplete burning of the material at less than a maximum velocity.
Luminol
A chemical process used to detect the presence of blood in conjunction with an alternate light source.
Machine Gun
A firearm which continuously fires ammunition at a high rate of fire when the trigger is pulled only once. See Automatic.
Magazine
The part of a repeating firearm which holds the cartridges or shells in position ready to be loaded one at a time into the chamber. (The magazine may be an integral part of a firearm or a separate device attached to the action.)
Magnetic
A type of proximity trigger that senses magnetic alterations in the area around the sensor. When this happens, the sensor causes a circuit to be completed, firing the device.
Magnetic attachment
A type of IED employment in which the device is attached to the target using magnets.
Magnum
A cartridge or shell with greater power than normal (i.e. .300 magnum rifle, 3 inch magnum shotshell).
Main charge
The bulk explosive component of an IED capable of providing an explosion by its own energy when initiated.
Main charge configuration
The arrangement or design of the main charge and other materials (usually metal) to create an effective weapon to attack personnel, vehicles, or structures.
Mainspring
A strong spring which activates the striker or hammer of a firearm.
Mandible
The lower jawbone of a vertebrate.
Manner of death (MOD)
The circumstances that caused a death to occur; may be natural, suicide, homicide, accidental, or undetermined.
Markings
The writing on ordnance items and packaged explosives that identify any, or all, of the following
Mass spectrometry
The action of vaporizing material and then measuring the molecular mass of the sample, resulting in the destruction of the evidence. The mass spectrometer is often used in conjunction with the gas chromatograph in the analysis of unknown substances.
Mastoid process
The conical projection below the mastoid portion of the temporal bone, behind the ear at the base of the skull.
Match
A long cord of hemp, flax or cotton, saturated in saltpetre, which burs slowly without a flame. (It was used to ignite powder in early firearms.)
Matchlock
A firearm action which relies upon a serpentine or S-shaped piece of metal to hold a smoldering match. By pressing the lower end of the serpentine, the upper end holding the burning match contacts the priming powder in the pan.
Maxilla
A pair of bones fused together that form the upper jawline.
Means
The part of the investigation that establishes the resources (components, knowledge, skill) used to assemble a bomb.
Mechanical energy
A retained spring in an IED or improvised weapon that acts as the energy source.
Mechanical explosion
An explosion characterized by a gradual buildup in pressure until that pressure exceeds the confines of the containment vessel, causing a mechanical rupture of the vessel.
Mechanical fuzing systems
An IED initiation system that utilizes mechanical energy to initiate the initiator.
Mechanical timer
A timing switch (e.g., clock, timer) constructed or modified so that physical contact between two parts of the timing device completes an electrical circuit initiating the device.
Medical examiner (ME)
The individual responsible for investigating all sudden, unexplained, unnatural, or suspicious deaths in a jurisdiction. The medical examiner is a public official and is generally a licensed physician who has completed training in the investigation of injuries and diseases that cause the death of humans.
Medicolegal death investigation (MDI)
The statutory responsibility to examine cases of sudden, unnatural, unexpected death; these statutory duties are delineated in myriad ways in various jurisdictions.
Mercury fulminate
A primary high explosive used in initiation systems and detonators to initiate secondary explosives.
Metal Cased
A bullet with a lead core and a solid metal jacket.
Metallic Cartridge
A cartridge with a metallic case. (Early cartridge cases were made of linen, paper, etc.)
Metallic Sight
A non-telescopic firearm sight.
Method of emplacement
A description of where the device was delivered, used, or employed.
Method of employment
A description of how the device was delivered, used, or employed.
Mid-Range
The point in the trajectory halfway between the muzzle and the target.
Military explosives
Explosives manufactured for military use.
Millimetre
A metric measurement equalling .03907 inches. (Its abbreviation is mm.)
Mine
In landmine warfare, an explosive munition designed to be placed under, on, or near the ground or other surface area and to be actuated by the presence, proximity, or contact of a person, land vehicle, aircraft, or boat.
Minutia
Characteristics that occur at the end of a ridge or at a bifurcation on a fingerprint.
Misfire
Failure of a cartridge to discharge after the firearmÕs firing pin has struck the primer. See Hangfire.
Mitochondrial DNA (mtDNA)
DNA that is transmitted only through the maternal line. Results can be determined from hair samples. Comparison samples can be obtained from any maternal relative for submission to the lab.
Mixture
The combination of two or more materials to form a new material in which the original components do not lose their identities.
Modus operandi (MO)
A criminal’s “signature” or preferred method of operation. Criminals tend to repeat their behavior, and a certain behavior becomes their MO—for example, car thieves gain access to vehicles using the same techniques, arsonists use the same methods/accelerants to start fires.
Mortar
A weapon, military or homemade, designed to launch an explosive charge to the target.
Motive
The part of the investigation that establishes why someone committed the crime.
Mouth
The open end of a cartridge case into which the bullet is inserted.
mulsion explosives
A class of high explosives consisting of liquid solutions of an oxidizer, fuel, and water blended with a sensitizer and an emulsion.
Mummification
The dehydration or desiccation of a body that occurs during the decomposition process.
Munitions
Ammunition, ordnance, or demolition charges containing explosives, propellants, pyrotechnics, initiating composition, or nuclear, biological, and chemical materials for use in military operations.
Mushroom
The shape many bullets assume when the tip expands upon striking. (Sometimes called mushroom bullets.)
Musket
A smoothbore shoulder gun (commonly used by military in the 17th, 18th and 19th centuries.)
Musketoon
A musket shortened for cavalry use.
Muzzeloader
A firearm that is loaded through the muzzle.
Muzzle
The forward end of a barrel.
Muzzle Blast
The violent disturbance in the atmosphere after discharge of a firearm, caused by release of powder gases into the air.
Muzzle Brake
A slotted device attached to the muzzle which softens the kick of the firearm.
Muzzle Energy
The energy of a bullet as it emerges from the muzzle. (Usually expressed in foot pounds.)
Muzzle Flash
The bright flash at the muzzle of a firearm resulting from burning of gases.
Muzzle Velocity
See Velocity.
Naked Bullet
A bullet not covered by a metal jacket or patch.
NamUs
The National Missing and Unidentified Persons System, a clearinghouse for missing persons and unidentified decedent records.
Narrative description
A written record that provides a format in which to prepare a written report that encompasses the entire scene investigation.
National Fire Protection Association (NFPA)
An international nonprofit association that provides codes and standards, research, training, and education on fire prevention.
National Insurance Crime Bureau (NICB)
An agency that collects information regarding stolen vehicles and maintains a website for investigators and the public regarding auto theft statistics.
National Integrated Ballistics Information Network (NIBIN)
A nationwide computer database maintained by the ATF and FBI that captures and stores digital images of expended bullets and cartridge cases.
Neck
The forward portion of a bottlenecked cartridge case. Also the portion of a rifle chamber in which the neck of the cartridge case rests.
Needle Gun
The first rifle known to use a bolt action.
Negative blast pressure
The reverse effect of positive blast pressure following an explosion in which the movement of air displaced by the shock front moves toward the epicenter of the explosion.
Nerve agents
A group of highly toxic organic esters of phosphoric acid derivatives that inhibit functioning of the acetylcholinesterase enzyme and can include tabun, sarin, soman, and V-series agents.
Ninhydrin
Also known as Ruhemann’s purple, a chemical that reacts with amino acids to provide a purple-blue colored image of latent fingerprints.
Nipple
A small metal tube extending through the breech of a percussion firearm through which the flame passes from the percussion cap to fire the powder charge.
Nitroglycerin (NG)
A very sensitive high-explosive liquid used in the manufacture of dynamite and some smokeless powders.
Non suicide
An IED in which the bomber does not intentionallv kill himself or herself as part of the attack.
Nonmagnetic attachment
A type of IED employment in which the device is attached to the target using nonmagnetic means.
Nonseated explosion
An explosion in which there is no physical evidence of a single location where the explosion occurred; often associated with fuel-air or dust explosions.
Nose
The point of a projectile.
Nuclear explosion
An explosion induced by either fission or fusion.
Nuclear materials
Materials that produce ionizing radiation or radioactivity that is capable of causing cellular change (damage) in living tissue.
Obturation
The expansion of the cartridge case which seals the chamber preventing gases from escaping.
Occipital bone
A compound bone that forms the posterior of the skull.
Odontology
The study of the teeth and the tissue that surrounds the teeth.
Omnidirectional effect
An aspect of main charge configuration in which the explosion is omnidirectional and expands in all directions.
Opacifier
A category of chemicals that are added to smokeless powder to provide a surface coating that keeps radiant heat from penetrating the surface of the powder, thereby reducing the chance of preignition.
Open device
An IED in which all the components can be completely seen and no attempt has been made by the builder to offer any concealment.
Open Sight
A non-telescopic firearm sight. See Sight.
Opportunity
A part of the investigation that establishes a window of opportunity for the subject to place or send the device to the victim.
Optical Sight
Usually a telescopic firearm sight. See Sight.
Organized search
A systematic visual examination of the area, in efforts to locate and secure evidentiary materials; types include grid, line/strip, or spiral search patterns.
Over-And-Under Gun
A firearm with two or more barrels placed one over the other.
Overhead
An IED emplaced above the intended target, that is, hanging from an overpass, or a roof, and so on.
Oxygen balance
A specific ratio of oxidizer to fuel in an explosive.
Painting with light
A time exposure on a camera by which an external flash is fired multiple times from different locations in order to illuminate the scene in the photograph.
Pan
The small dished container located on the side or top of a matchlock, wheel-lock or flintlock forearm used to hold the priming powder charge.
Parallax
The displacement of an object viewed from two different position. (For example, when using a telescopic sight, the apparent movement of the reticule in relation to the target when the eye is shifted to a different position.)
Parkerizing
A non-reflecting, rust-preventive finish used on the metal of firearms.
Passive infrared
A sensor that detects movement of a heat source. When a change in ambient temperature is detected, the sensor acts as a trigger to initiate the IED.
Passive stains
Stains created by drips, flows, pools, and saturation.
Passive/booby trap systems
An explosive or nonexplosive device or other material deliberately placed to cause casualties when an apparently harmless object is disturbed or a normally safe act is performed.
Patch
A piece of leather or cloth. The patch is greased and placed around a bullet before ramming it down the barrel of a muzzleloader.
Patch Box
Covered compartment in the buttstock of a muzzle-loading rifle used to carry patches or other small items.
Pathologist
A licensed physician who specializes in the study of diseases and injuries as related to human deaths.
Pattern
Distribution of shotgun pellets. This is measured at a standard distance of 40 yards (37 m) using a 30 inch circle (762 mm). (A full choke charge should throw a patter of at least 70 percent of the shot into the 30 inch circle at a distance of 40 yards.)
Pattern analysis
Use of prior actions and activities to identify trends in activities or behaviors. Once identified, these patterns can be used to predict future bomber/criminal/terrorist actions and to plan intelligence, surveillance, and reconnaissance activities.
Penetration
The distance travelled by a projectile from the point where it strikes the target to the point where it stops.
Pennsylvania Rifle
See Kentucky Rifle.
Pentaerythritol tet ran it rate (PETN)
A detonator-sensitive high explosive that is often used as the base charge in detonators, in detonating cord, and sheet explosives and is combined with TNT to form boosters.
Percussion Cap
A small metal explosive-filled cup which is placed over the nipple of a percussion firearm. (As the cap is struck by the hammer, it explodes and sends a flame through the flashhole in the nipple to the main powder charge.)
Percussion primer
A device that serves as an igniting element, usually initiated by mechanical means; for example, shotshell primer is fired by a firing pin.
Permissible explosives
A class of explosives that have been tested and approved for use in underground mines by the Mine Safety and Health Administration.
Person borne IED (PBIED)
An IED worn by a person, either willing or unwilling, such as a vest, belt, backpack, in which the person houses the whole IED or principal IED components and/or serves as the delivery or concealment means for explosives with an initiating device. A PBIED is often initiated by the person wearing the IED (suicide), however, not all PBIEDs are triggered by the person wearing the IED (proxy).
Personal protective equipment (PPE)
Articles, such as disposable gloves, masks, and eye protection, that are utilized to keep biological or chemical hazards from contacting the skin, eyes, and mucous membranes and to avoid contamination of the crime scene. Public safety agencies are required to provide PPE for all first responders.
Perspective grid
A measurement system involving photographing a known scale within a scene and using that scale to measure items in the photograph; also known as photogrammetry.
Phishing
An Internet fraud scheme that utilizes fake websites that appear to be legitimate bank or credit card sites.
Photo Hash powder
An extremely sensitive low explosive used in legal and illegal fireworks.
Photographic log
A written record that provides organization to the photographs.
Physical evidence
Any and all objects that can establish that a crime has been committed or can provide a link between a crime and its victim or a crime and its perpetrator, and are used in the discovery of the facts.
Physical evidence
Any material that is solid, liquid, or gaseous that may aid in the determination of truth during an investigation.
Pistol Grip
See Grip.
Pitch
The angle of the barrel of a rifle or shotgun away from the angle of the stock. (It is measured by placing the butt of the stock on the floor and measuring the angle of the muzzle away from a line perpendicular to the floor.)
Pixilated image
In digital photography, an image that is enlarged to the point that the individual pixels making up the image are seen.
Placed ordnance
Regarding military ordnance, explosive ordnances t hat are placed /secreted in, on, or above the ground, which are commonly referred to as landmines.
Plain impressions
Inked fingerprints that are obtained by simultaneously pressing all four digits of the hand into the ink and then onto a fingerprint card.
Plasticizers
A category of chemicals that are added to smokeless powder to soften the propellant, which assists in the manufacturing processes when it is extruded and cut into various shapes.
Platter charge
The use of an explosive used to propel a metal plate toward a target in a manner where the plate remains intact. This is also known as the Misznay-Schardin effect.
Point detonating
A fuze that is located in the forward end of a munition and is designed to be actuated as a result of impact.
Point of convergence
The common point or area on a two-dimensional surface over which the directionality of several blood drops can be determined by using strings to re-create the flight of blood (or another substance).
Point of impact (POI)
In motor vehicle investigations, the specific point where the automobile was impacted.
Point of origin or impact
In bloodstain analysis, the common point or area in three-dimensional space resulting from the retracing of the trajectories of several blood drops; also the location where two objects collided.
Point-initiating, base-detonating fuze
A fuze with initiating components located in the nose of the munition and the detonating components located in the base of the item.
Polar coordinates
A measurement system using a transit or compass to measure angles taken from a known point to two fixed points. Similar to triangulation but it covers larger areas.
Armed and functioning
An electrical, mechanical, or chemical fuzing system that is running or working to a preset time delay that unless stopped by an outside force will cause the initiator to function.
