Accompanying Elements

From casework statistics the unique particles (those containing the combination lead, antimony and barium, and those containing antimony and barium) occur in the ratio 7 3, respectively. Approximate percentages for indicative particles are lead-only 55 lead, antimony 20 lead, barium 8 antimony-only 7 barium, calcium, silicon 5 barium-only 5 . Table 19.3 gives an indication of the levels of the primary elements in each particle type. Table 19.4 gives an indication of the levels of accompanying...

Firearms Ammunition

.22 LR caliber .22 long rifle caliber Carbine a shorter length, lightweight rifle JHP bullet jacketed hollow point bullet JSP bullet jacketed soft point bullet K kurtz (short) L long Machine pistol handgun-style pistol capable of automatic fire Mag magnum NCNM noncorrosive, nonmercuric P parabellum Rem Remington Rev revolver RNL bullet round-nosed lead bullet S & W Smith and Wesson SMG submachine gun Spl special SWC bullet semi-wad-cutter bullet T bullet tracer bullet TMJ bullet total...

Persistence

The persistence of FDR on the hands has been studied by many workers and while there are wide variations in the literature (1 to 24 hours) the majority opinion is in the region of 1 to 3 hours from the event to the sampling of the suspect.177-179 Beyond 3 hours it is unlikely that residue will be detected on the hands of live suspects. Persistence on face, head hair, and clothing has not been studied, but it is highly likely that FDR will persist on these areas for longer periods than on the...

About the Author

Jim Wallace is a retired U.K. forensic scientist who worked in the firearms section of the Northern Ireland Forensic Science Laboratory for almost 25 years. During this time he experienced many complex and controversial cases, the vast majority of which were terrorist-related incidents. His main interests include the chemical examinations relating to firearms casework, research and development work arising from same, crime scene examination, health and safety issues, quality assurance,...

Particle Classification Scheme

The original particle classification scheme192 has been revised based on casework experience, research work on blank cartridges, and so forth, and a detailed analysis of 14 years of casework results. The particle classification scheme used in Northern Ireland since 1984 is given in Table 19.5. The indicative particles are in tentative order of decreasing significance. The classification scheme is based on discharge residue particles from modern primed brass-cased ball ammunition. It is only...

Morphology and Size

Apart from various gases four types of particles have been detected in firearm discharge residue 4. Fragments of smokeless powder As a general rule greater than 70 of the particles are spherical. They may be perfect spheres or they may be distorted in some way. Three-dimensional roundness is the basis for this classification. The surface of the particles may be smooth, fuzzy, scaly, or have smaller spheres on their surface. Sometimes they are perforated, capped, broken, or stemmed. The vast...

Firearm Coatings

The surface coating of a random selection of firearms was examined and the results are given in Table 20.10. The elements detected in Table 20.10 do not fully reflect the wide range of elements mentioned in Chapter 15. It is possible that such coatings could, on rare occasions, make a contribution to the elemental content of some of the particles, or could be deposited directly on to the hands from handling the firearm. Surface coatings have the potential to make a contribution, particularly...

Fireworks

During the troubles in Northern Ireland only indoor-type fireworks could be purchased without a special license. Analysis of particles originating from the use of indoor-type fireworks showed only a few spherical particles the majority was large irregularly shaped flakes. The elements aluminum, barium, chlorine, chromium, iron, potassium, sulfur, and antimony were detected, all of which were at a major level. Analysis of particles originating from the use of outdoor fireworks revealed that the...

Distribution

Distribution may be defined as the areas where FDR is deposited and the concentration in those areas. It was thought that rifles and handguns when fired in the normal manner would produce different distribution patterns on the firer, with rifles more likely to deposit FDR on the face than handguns. It was also thought that the distribution on the hands could determine whether or not the test subject had discharged or merely handled a gun. On firing a gun more residues are expected to be...

Particles from Handling Ammunition

Particles on the outside surface of newly acquired, unopened ammunition were examined in order to determine if the ammunition was contaminated with discharge residue in the factory. Munitions and firearms manufacturers do test-fire their products. Results are given in Table 20.1. The majority of the lead-only, antimony-only, and lead, antimony particles that were spherical would be classified as indicative of FDR. However, they were accompanied by particles whose morphology was inconsistent,...

References

McQuillan, Discharge Residues from Cartridge-Operated Industrial Tools, Journal of the Forensic Science Society 24 (1984) 495. 192. G. M. Wolten, R. S. Nesbitt, A. R. Calloway, G. L. Lopel, and P. F. Jones, Final Report on Particle Analysis for Gunshot Residue Detection, The Aerospace Corporation, El Segundo, CA. Aerospace report no. ATR-77 (7915)-3 (September 1977). 193. R. Harris, Pyrotechnic Compositions, Chemistry in Britain (March 1977) 113. 194. Kirk-Othmer...

Info

The Firearms Act (Northern Ireland) defines a firearm as a lethal barreled weapon of any description, from which any shot, bullet or other missile can be discharged. This very loose definition leaves scope to cover almost every conceivable type of device that incorporates a tube through which any missile is projected. Could a blowpipe used to discharge poisoned darts be described as a firearm It is gas operated, has a barrel, and the projectile is designed to be lethal. Although the blowpipe...

Formation

The development of the particle analysis method for FDR detection and identification involved consideration of how the particles are formed and of their physical and chemical nature.170171 At the present time the exact mechanism(s) of formation of the particles can only be deduced from considerable practical experience and limited experimental work, most of which, if not all, has been concerned with the elemental content of FDR particles. An extensive and very valuable study of the nature of...

Frangible Bullets

Until recently these were usually confined to .22 caliber and used in shooting galleries. They are designed to disintegrate on hitting the target and consequently will not ricochet. They consist of particles of iron or lead bonded in some synthetic material. One manufacturer describes a .22 short bullet as being lead or iron bonded with lanolin.96 Such bullets are also used for training purposes. Frangible bullets have recently become popular in a range of calibers due to the trend toward...

Effect of Water on FDR

It has been observed that in casework involving examination of damp or wet clothing for FDR, the success rate was very low (such clothing would be dried before sampling). Possible explanations are that the particles are chemically attacked by water, that the water removes the particles by physical disturbance, for example, washed away by rain, that the water moves the particles farther into the fabric of the garment and the sampling procedure fails to recover them, or that all the cases...

Gas Chromatographymass spectrometry

A gas chromatograph is an apparatus consisting of an injection port connected to a column that has a detector at its outlet end. The column is contained in an oven that is electrically heated, either isothermally or at a programmed rate. A stream of inert carrier gas, usually helium, is introduced into the injection port and flows through the column and detector. The injection port is a heated region that is sealed from the outside environment by a silicone rubber septum through which the...

Antimony Free Primers

As mentioned previously it was noted in casework that Yugoslavian 7.62 x 39 mm caliber nny 82 ammunition produces discharge particles containing barium, despite the fact that there is no barium in the primer, although it is present in the propellant. This indicates that the propellant can make a contribution to the elemental content of the discharge particles. In some incidents involving the use of ammunition with antimony-free primers, discharge particles containing antimony have been detected...

DDischarge of a Firearm

The firing mechanism of a firearm consists of a mechanical device which causes a hammer to fly forward and deliver a blow to the firing pin when the trigger is pulled. In some firearms the hammer and firing pin are made in one piece. The firing pin goes through a small hole in the breech face and strikes the primer cup. The well-known phrase lock, stock and barrel originates from firearms the lock is the mechanism of the firearm, the barrel is the tube through which the bullet travels, and the...

Flares

Flares have several uses including signaling and illumination and there are several means of launching, including handheld, rocket, and specifically designed pistols (for example, Verey pistol). The use of flares in Northern Ireland is very limited, with the security forces using them occasionally. They have in rare instances been used illegally. Analysis of two handheld types showed that the vast majority of the discharge particles were irregular with several large flakes present. Elemental...

Deposition

There is evidence to suggest that the FDR on the firer's hand is blasted on to the hand during the firing process and that residue settling from the atmosphere does not appear to contribute. Copious amounts of FDR issue from the muzzle but play a secondary role in hand deposits. The hand deposits are mainly emitted from openings around the breech and ejection port in self loading firearms and from the flash gap between the cylinder and barrel in revolvers.174 Such residues can also be deposited...

Multiple Loads

Ammunition has been manufactured with more than one bullet loaded inside the cartridge case. The idea is to increase the stopping power of the ammunition. Up to four bullets loaded in tandem within a single cartridge case are known, with the bullets reduced in size and weight compared to a normal bullet loading. Such rounds of ammunition are rare. If a person were shot at close range with one round of such ammunition there would be a single entrance wound and more than one bullet could be...

Special Purpose Ammunition types

The Glaser safety slug is a high velocity projectile with a copper jacket filled with very small lead shot pellets and sealed at the tip with a frangible plug. On striking the target the pressure on the tip prevents it from fragmenting, but on penetrating the target the plug fragments causing the bullet to disintegrate, thereby releasing its shot charge. This substantially increases its stopping power by delivering all of its energy to the target, preventing overpenetration and substantially...

Gas Chromatography Thermal Energy Analyzer

Details of the gas chromatography thermal energy analyzer (GC TEA) system are as follows. The instrumentation is a Hewlett Packard 5890 GC with a Thermedics 543 Thermal Energy Analyzer connected to a Hewlett Packard 3393A integrator. The system also incorporates a Hewlett Packard 7673A autoinjector. The TEA was modified according to the alterations detailed in reference 188. The conditions are Column 15M RTX 1 DM Silicon oil, 0.25 mm inter- Initial temperature First ramp Second ramp 35 C to 165...

History of Firearms

The history of firearms is long and complicated, encompassing innovations and developments in ammunition from crude black powder muzzle loaders to modern brass-cased, centerfire cartridges using smokeless propellant, in ignition systems from a glowing twig touching gunpowder through a simple flash hole in the barrel to a firing pin which strikes and crushes the priming mixture thereby instantly igniting the propellant charge, in mechanical developments from the simple metal tube attached to a...

Scanning Electron Microscopy

SEM EDX analyses were performed using a Camscan series 2 scanning electron microscope connected to a Link AN 100000 energy dispersive X-ray analyzer. For automatic detection an automatic residue detection system (ARDS), developed at this laboratory, was employed the details of which are given in reference 187. For manual operation the following conditions apply 29 mm working distance 1-1.25 x 100 A emission x 1,000 magnification 25 kV accelerating voltage 0 tilt and resolution and absorbed...

RPG Rocket Launcher

The Soviet RPG7 antitank rocket launcher using a PG7 tank rocket has been used during the terrorist campaign in Northern Ireland. It is a long weapon that sits on top of the shoulder when in use and exhausts to the rear of the firer. After incidents in which the RPG7 was used, the laboratory was requested to examine swabs and clothing from suspects, for discharge residue from the launcher. Because the exhaust from the weapon emerges a considerable distance to the rear of the firer, and the...

Components

Also present in ammunition is a range of lubricants (greases and waxes) usually confined to unjacketed bullets, as well as various sealers, varnishes, and lacquers (often colored) that are used for several purposes. These include prevention of the ingress of moisture or oil, anticorrosion measures, to act as a visual aid in the manufacturing process, to provide additional resistance of the bullet to the pressure generated by the propellant gases, and color coding to identify the type of...

High Performance Liquid Chromatography

In liquid chromatography the mobile phase is a liquid. The stationary phase is a solid contained inside a long narrow tube called the column. Separation of mixtures occurs during passage through the column. The separation can occur by different mechanisms depending on the type of material in the mixture and the column, for example, adsorption, exclusion, ion exchange, partition. Whatever the mechanism, the volume of mobile phase at which a component elutes is constant and characteristic of that...

Homogeneity of Propellants

To investigate the feasibility of conducting chemical comparisons between propellants detected in casework and suspect ammunition, it was decided to determine variations from granule to granule in a single round of ammunition and then to compare burned discharged and unburned propellants, to determine what, if any, difference was caused by the discharge process. Analysis of 20 propellant granules from a single round of ammunition gave the following results. Diphenylamine and three...

Propellant Analysis

Gevelot Headstamp

The samples were granules of propellant recovered from materials shot at close range, mainly clothing from injured persons. Consequently, in the vast majority of instances the type of ammunition is not known. It must be noted that granules found may not necessarily be representative of the bulk, as composition can vary from granule to granule, and also that these are discharged propellant granules and in the act of discharge surface coatings can be blown or burned off.199 Table 21.1 and Table...

Particle Analysis Method

Back Scattered Electrons

This method employs a scanning electron microscope equipped with elemental analysis capability SEM EDX and combines details of the morphology and elemental composition of individual FDR particles. A particle classification scheme was developed and is based on the elemental composition and morphology of individual FDR particles and is used to classify particles as one of the following a of nonfirearm origin, b consistent with originating from the discharge of a firearm, or c definitely from the...

History of Bullets

The first projectiles to be discharged from any type of firearm were stones, feathered iron arrows, and iron shot. These were discharged from cannons.18 The first handheld firearms had bore diameters between 1.5 and 2.0 and suitable small round stones were used as projectiles. The earliest use of lead in bullets would appear to have been about 1340 and these consisted of spherical lead bullets.19 Firearms of this era were large and heavy and from this time to the present day there has been a...

Bullet Weight Loss on Firing

A test was conducted to determine the weight loss of some bullets after discharge. Results are given in Table 20.3. From the limited experimental data it would appear that, as expected, the full metal jacketed bullets lose less than the soft unjacketed bullets. The FMJ bullet with its base enclosed lost less than its equivalent with its base exposed. This is also predictable as the exposed base is subject to erosion during discharge. The .38 SPL P unjacketed bullet Table 20.1 Particles on New...

History of Ammunition

The self-contained metallic cartridge is a relatively recent development in historical terms. Gunpowder has been in use as a firearms propellant for about 670 years, but the metallic cartridge is only about 160 years old. The modern self-contained metallic cartridge was perfected about 122 years ago and high-velocity types with smokeless powders were developed about 102 years ago.23 Prior to the introduction of a self-contained cartridge, firearms were muzzle-loaded by pouring a measured amount...

Firearms Ammunition and Gunshot Residue

Taylor amp Francis Group, an informa business 6000 Broken Sound Parkway NW, Suite 300 2008 by Taylor amp Francis Group, LLC CRC Press is an imprint of Taylor amp Francis Group, an Informa business No claim to original U.S. Government works Printed in the United States of America on acid-free paper International Standard Book Number-13 978-1-4200-6966-2 Hardcover This book contains information obtained from authentic and highly regarded sources Reasonable efforts have been made to publish...

Surface Coatings

The reasons for treating the surface of a firearm is to get rid of reflections from bright surfaces which could dazzle the firer and or reveal the firing position to the enemy or game, to improve the appearance of the firearm, and more importantly to provide a degree of protection against corrosion. Early firearms had no finish at all and rusted rapidly when exposed to black powder residues and atmospheric moisture. A process known as browning artificial rusting was the first attempt at a...

Primer Cups Caps

Boxer Primer

Priming compositions for centerfire ammunition are housed in small metal cups which fit into a recess, called the primer pocket, in the center of the base of the cartridge case. In rimfire ammunition the priming composition is housed inside the cartridge case in the hollow perimeter of the base. The ideal primer cup metal should expand easily to provide a gas-tight seal, be strong enough to withstand the blow from the firing pin, and also strong enough to withstand the explosion of the priming...

Firearm Construction Materials

A range of different grades of steel are used in the manufacture of a single firearm. Chromium-molybdenum steel is the basic material for the modern firearms industry. It possesses good tensile strength, resists wear, and has good machining properties. Most .22 rimfire caliber guns, shotguns, and low pressure centerfire barrels are made from carbon steels. High-pressure centerfire barrels for sporting use are normally made from chromium-molybdenum-vanadium steel. The grades of steel used for...

Bullets

Every bullet type is designed for a specific purpose and the range of bullet designs available for a single firearm can be substantial. Figure 11.1 illustrates some different physical designs of round nose bullets.63 This only illustrates a variation of types within one design of bullet that is available in a range of calibers. Variation of types occurs within other designs of bullet, for example, truncated cone, cone- or spire-point, spitzer, flat nose, semi-wad-cutter, wad-cutter, round ball,...

Analysis of a Baton Round

As a consequence of a case in which the suspect alleged that the FDR on his person originated from contact with the inside of a police vehicle, from which baton guns had previously been fired, it was necessary to conduct a detailed examination of the baton round and the crime ammunition. Antimony was detected in the residue particles on the suspect and it was known that the baton round does not have antimony in the primer. However, it was required to prove that there was no antimony in any part...

Cartridge Cases

The cartridge case is designed to house the primer, propellant, and to securely retain the bullet in the neck of the case. Cartridge case design is affected by various factors, the most important being Type of ignition system, that is, Boxer primed or Berdan primed. The vast majority of cartridge cases are made of brass approximately 70 copper and 30 zinc but other materials such as steel, coated with either zinc, brass, gilding metal, copper, lacquer or blackened copper nickel-plated brass...

Priming Compositions

Priming compositions for firearms ammunition are mixtures which, when subjected to percussion, provide a sudden burst of flame that serves to ignite the propellant within the cartridge case. A priming composition must deliver a relatively large volume of hot gases and hot solid particles without the development of a detonating wave. The ideal priming composition would consist of a cheap, readily available, relatively safe to handle, simple chemical compound of uniform granulation which when...

Toy Caps

Six different brand names of caps designed for use in toy guns were examined, two of which were the paper roll type the others were the individual plastic cup type that is placed on the anvil of the toy gun. Analysis of discharge particles revealed that both spherical and irregular particles were present, with approximately 1 in 12 spherical. The particle size range was from 3 to 160 m. The elements detected were aluminum, calcium, chlorine, copper, iron, potassium, magnesium, phosphorus, lead,...

Discharge Residue from Black Powder Ammunition

In previous casework in which the majority of the FDR particles contained potassium and sulfur, frequently at high levels, it was thought that the ammunition responsible probably contained black powder. In most of the cases the type of ammunition was not known, whereas in others the sampling and analysis of the residue from the interior of the spent cartridge cases confirmed the presence of black powder. This posed the question do potassium and sulfur always occur, often at high level in...

Flameless Atomic Absorption spectrophotometry

Amplifier Spectrophotometer

The FAAS method offers similar detection limits to NAA and is suitable for the determination of low levels of lead. Equipment costs are reasonable and the instrumentation is commonplace in many analytical laboratories. A large number of metallic elements, over a wide concentration range, extending down to ultra-trace level, can be analyzed, thus making the technique versatile and useful for other forensic applications as well as FDR detection. Apart from cost, the main advantages are...

Blank Ammunition

One definition of a blank cartridge is a percussion initiated cartridge that does not have a bullet or missile that is designed to be lethal. However, blank cartridges are dangerous if misused and serious injuries and a few fatalities have resulted from their misuse at close range. A dummy round is not a blank as it is completely inert. Some blank cartridges, designed for use in cartridge tools, if discharged in a firearm may seriously damage the firearm and possibly injure the firer. Such...

Sample Collection

Some form of kit containing sampling materials is normally prepared commercially, or by police forces, or by forensic laboratories for the purpose of sampling suspects for FDR.180-182 Kit design considerations include a avoiding contamination from external sources and cross contamination between sampling areas, b lifting efficiency, c matrix compatibility with subsequent laboratory procedures, d ease of use and preparation, and e cost, purity, availability of materials. Cotton wool and dilute...

Quadraximum Bullet

The Identification of Small Arms Ammunition, Department of Chemistry and Metallurgy, Royal Military College of Science. Technical report AC R 31 August 1979 2-C-1, 2-C-2. 64. The Identification of Small Arms Ammunition, 2-C-5. 65. Finn Aagaard, Trophy Bonded Bullets, American Rifleman Magazine May 1987 34. 66. Ross Seyfried, The 'Inside' Story Big Game Bullets, Guns and Ammo Magazine March 1987 62. 67. Private communication, 1981. 68. P. Labbett, Cartridge Corner, Guns Review Magazine...

History of Gunpowder

A mixture known as black powder revolutionized the art of warfare whenever it was applied to the propulsion of missiles. Black powder is a mixture of potassium nitrate saltpeter , charcoal, and sulfur in varying proportions, granulation, and purity. A typical composition of a modern black powder is saltpeter 75 , charcoal 15 , and sulfur 10 .7 A mixture of saltpeter, charcoal, and sulfur with other ingredients was used in China and India in the eleventh century for incendiary and pyrotechnic...

Incendiary Bullets

Incendiary bullets are used against flammable targets and have an incendiary composition in the nose portion which is ignited on impact. Incendiary bullets are usually encountered in rifle calibers. The best-known incendiary agent is magnesium, which melts about 650 C and once melted is very easily ignited. Incendiary compositions capable of being easily ignited and which can evolve enough heat to melt the magnesium are used. Some examples of incendiary compositions are71 Thermite Iron oxide...

Bullet Hole Perimeters

The sodium rhodizonate test for lead197 is routinely used in many forensic laboratories for confirmation of bullet damage and range of fire determinations. In a number of cases the test failed to indicate the presence of lead on the perimeter of holes that had a distinct bullet wipe. The bullets involved in these cases were all copper jacketed FMJ . As the test is routinely used in this laboratory, the negative findings from known bullet holes caused concern. It was decided to instigate a...

Harrison and Gilroy Method

In 1959, Harrison and Gilroy introduced a method based on the detection of the metal-containing components of FDR.124 The metallic components involved, namely, lead, antimony, and barium, originate from the primer and the bullet lead and antimony . The method is based on colorimetric spot tests and involves swabbing the suspect's hands with cotton cloth damped with 0.1 M hydrochloric acid. The swab is allowed to dry and is then tested with one or two drops of a 10 alcohol solution of...

Resorcinol Stabilizer In Smokeless Powder

Smokeless Gunpowder Appearances Flakes

Small arms ammunition propellants may be defined as explosive materials which are formulated, designed, manufactured, and initiated in such a manner as to permit the generation of large volumes of hot gases at highly controlled, predetermined rates.55 Ideally, a propellant would be a single, solid, nontoxic chemical compound that is stable, easy to store, easy to ignite, of compact mass, and so forth, which is cheap and simple to prepare from readily available materials and which on combustion...

Firearm Discharge Residue Detection Techniques

Gunshot Residue Paraffin

Forensic firearms casework examination encompasses the following major areas of work Examination of firearms, ammunition, and associated items Examination of firearms and associated items for anything else of forensic interest, e.g., blood, hairs, fibers, glass, fingerprints Comparison macroscopy of spent bullets and spent cartridge cases Identification of weapon types from spent cartridge cases and spent bullets Examination of swabs and clothing from suspects for firearm discharge residues...

Tracer Bullets

When fired, a tracer bullet leaves a visible trace behind it so that the trajectory can be seen and the aim corrected if necessary trajectory tracer . A tracer bullet has a cavity at the base which is filled with a mixture of substances that are ignited by the propellant. The bullets are available in a range of rifle, pistol, and revolver calibers, although they are more common in rifle calibers. The tracer composition is frequently housed in a metal canister placed inside the base cavity....

BFirearms

It is probable that the word firearm originated from the flame produced at the muzzle end muzzle flash when a firearm is discharged the muzzle is the front part where the bullet emerges from the barrel Photograph 1.1 . The word gun is a widely accepted alternative name to firearm, although it is also used in many nonfirearm terms, for example, grease gun, spray gun, flame gun, nail gun, insecticide gun, paint gun, stun gun, etc. A stun gun is a weapon designed to disable a victim temporarily by...

Armor Piercing Bullets

Armor-piercing AP ammunition has a projectile or projectile core constructed entirely from a combination of tungsten alloys, steel, iron, brass, bronze, beryllium copper, or depleted uranium. The most effective AP bullets are usually confined to rifle bullets, as velocity and range are important factors in AP requirements. Some revolver and pistol ammunition is described as metal piercing but, although it would be effective against vehicle bodywork and some body armor, it would be ineffective...

Paraffin Test

The detection of nitrates and nitrites present in FDR using a color reaction with diphenylamine in sulfuric acid was first applied to firearms related examinations about 1911, and in 1914 Doctor Iturrioz used paraffin wax as a lifting medium for propellant residue on clothing prior to treatment with Diphenylbenzadene HNO3 colorless Diphenylbenzadene HNO3 colorless Figure 16.1 Quinoil immonium ion blue . Figure 16.1 Quinoil immonium ion blue . diphenylamine sulfuric acid reagent. The use of...

Caseless Ammunition

Fragile Caseless Rifle Ammo

Current trends in firearms and ammunition are toward lighter and easier to carry firearms and ammunition. These include the use of various plastics in the manufacture of firearms and some large, well-known manufacturers are experimenting with the development of caseless ammunition combustible cartridge cases and primers which, if viable, will involve major design changes in the mechanism of firearms. The disadvantages of caseless ammunition include the very high cost of totally new weapons and...

Quantity and Composition

Bulk elemental analysis methods have been employed by many workers to do quantitative studies of the amount of residue deposited on the firing hand. Surveys based on indoor firings of a range of handgun ammunition combination and sampling of the firing hand using a variety of sampling techniques, followed by analysis using differing sample preparation analytical methods, gave the following widely varying results for residue collected immediately after firing from one to six shots170 Lead 0.45...

Neutron Activation Analysis

Neutron activation analysis NAA is one of the most sensitive analytical techniques for many elements. A major breakthrough came in 1964 when NAA was applied to the quantitative detection of antimony and barium in FDR.130 Antimony is the most valuable elemental indicator for FDR, because lead and barium are more common in occupational and environmental surveys. The method is based on the fact that when a sample is irradiated in a nuclear reactor for a specific length of time, atoms of some...

Exploding Bullets

Exploding bullets are not a recent concept. About the middle of the nineteenth century two types of exploding rifle bullets were invented, one using a percussion cap and black powder and the other using mercury fulminate. Figure 11.5 illustrates both types. During World War II several types of exploding rifle bullets were developed containing an integral striking pin. One contained a firing pin inside a brass bushing. The bushing was free to slide backward and forward inside a copper cup which...

Blank Cartridges

Doubts initially arose about the particle classification scheme when the NIFSL experienced a case involving the examination of a suspect's upper outer clothing for FDR, in which the only discharge particle types detected were lead only and barium, calcium, silicon the barium, calcium, silicon type was considered to be unique to the discharge of a firearm at the time . The size and appearance of the particles were consistent with FDR residue however, none of the other particle types were...

Poisoned Bullets

Poisoned Bullets

The concept of a poison contained within a bullet is not new and has been experimented with over a long period of time. As all poisons, in the quantities capable of being administered via a bullet, take some time to kill, the tactical use of such ammunition is of limited military or civilian use. However, it is an attractive concept for an assassin. If the bullet itself fails to kill, the backup system of the poison offers a twofold method of attack. In 1892, Lagard transmitted anthrax to...