Firearms and Ballistics~tqw~-darksiderg

Firearms and Ballistics~tqw~-darksiderg

(Parte 1 de 5)

Handbook of Firearms and Ballistics

Examining and Interpreting Forensic Evidence

Second Edition Brian J. Heard

A John Wiley & Sons, Ltd., Publication

Handbook of Firearms and Ballistics Second Edition

Handbook of Firearms and Ballistics

Examining and Interpreting Forensic Evidence

Second Edition Brian J. Heard

A John Wiley & Sons, Ltd., Publication

This edition fi rst published 2008, © 2008 by John Wiley & Sons Ltd

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Library of Congress Cataloguing-in-Publication Data Heard, Brian J.

Handbook of firearms and ballistics : examining and interpreting forensic evidence / by Brian J. Heard. p. cm. Includes index. ISBN 978-0-470-69460-2 1. Forensic ballistics. 2. Firearms. 3. Firearms–Identification. I. Title. HV8077.H43 2008 363.25′62–dc 2 2008029101

ISBN: 978-0-470-69460-2 A catalogue record for this book is available from the British Library. Set in 10.5/12.5 Sabon by SNP Best-Set Typesetter Ltd, Hong Kong.

Printed in Singapore by Markono Print Media Pte Ltd. First Impression 2008

Contents

Developments in Forensic Science ix Acknowledgements xi Foreword xiii

1 Firearms 1 1.1 A Brief History of Firearms 1 1.2 Weapon Types and Their Operation 19 1.3 Proof Marks 32 Further Reading 42

2 Ammunition 43 2.1 A Brief History of Ammunition 43 2.2 Ammunition Components 48 2.3 Non-toxic Shot 7 2.4 A Brief History of Propellants 80 2.5 Priming Compounds and Primers 86 2.6 Headstamp Markings on Ammunition 94 Reference 9

3 Ballistics 101 3.1 Internal, External and Terminal Ballistics 101 3.2 Internal Ballistics 102 3.3 External Ballistics 109 3.4 Terminal Ballistics 124 References 143

4 Forensic Firearms Examination 145 4.1 A Brief History of Forensic Firearms Identifi cation 145 4.2 Rifl ing Types and Their Identifi cation 154 4.3 Fluted, Annular Ringed, Helical, Perforated and Oversized Chambers 166 4.4 Basic Concepts of Striation Matching 170 4.5 Basic Methodology Used in Comparison Microscopy 182 4.6 Mathematical Proof of Striation Matches 186 4.7 Accidental Discharge 191 4.8 Identifi cation of Calibre from the Bullet Entry Hole 197 4.9 Ricochet Analysis 200 4.10 Bullet Penetration and Trajectory through Glass 204 References 208 vi CONTENTS

5 Range of Firing Estimations and Bullet Hole Examinations 211 5.1 Introduction 211 5.2 The Use of X-ray Photography 212 5.3 Range of Firing Estimations for Pistols and Rifl es 219 5.4 Chemical Tests for Range of Firing Estimations and Bullet Entry/Exit

Hole Identifi cation 227 5.5 Range of Firing Estimations for Shotguns 233 References 239

6 Gunshot Residue Examination 241 6.1 Introduction 241 6.2 Formation of Discharge Residue 241 6.3 Distribution of GSR Particles 242 6.4 Identifi cation of GSR Particles 243 6.5 The Use of the SEM for GSR Detection 247 6.6 Sample Collection 248 6.7 GSR Retention 251 6.8 Conservation of GSR Particles on the Hands 251 6.9 GSR Distribution on the Hands 252 6.10 Identifi cation of Type of Ammunition, Country of Origin from

GSR Analysis 255 6.1 Environmental Contaminants 256 6.12 Sources of Elements Commonly Found in Lead-Based GSRs 257 6.13 Extending the Recovery Period for GSR 259 References 268

7 Gun-Handling Tests 271 7.1 Introduction 271 7.2 Methodology for Ferrozine Use 274 7.3 Case Notes 275 References 276

8 Restoration of Erased Numbers 277 8.1 Introduction 277 8.2 Methods Used for Removal of Serial Numbers 277 8.3 Theory behind Number Restoration 278 8.4 Non-recoverable Methods of Number Removal 279 8.5 Practice of Number Restoration 280 8.6 Chemical Methods of Restoration 280 8.7 Reagents Used for Various Metals 281 8.8 Electrolytic Methods of Restoration 283 8.9 Reagents Used 283 8.10 Ultrasonic Cavitation for Restoration 284 8.1 Magnetic Particle Method for Restoration 284 8.12 Other Methods of Restoration 285 8.13 Laser-Etched Serial Numbers and Bar Codes and Their Restoration 286 References 288

9 Qualifying the Expert and Cross-Examination Questions 291 9.1 Introduction 291 9.2 General Background Questions 293

CONTENTS vii

9.3 Comparison Microscopy 294 9.4 GSRs 297 9.5 Ferrozine Test 300 9.6 Standard of Review: ‘Daubert Trilogy’ 300 References 302

10 Classifi cation of Firearm-Related Death 305 10.1 Multiple-Shot Suicides 307 References 309

1 Glossary 31 Appendix 1 Important dates in the History of Firearms from 1247 3 Appendix 2 GSR results for Chinese and USSR ammunition 341 Appendix 3 Primer content of some cartridge-operated nail guns 345

Appendix 4 Commercial and General Abbreviations for Bullet Confi gurations 347

Appendix 5 Trade Names 353 Appendix 6 Gun Marks 373 Appendix 7 Powder Burn Rate 377 Appendix 8 Hearing Loss 381 Appendix 9 General Firearms Values Conversion Table 389 Index 393

Developments in Forensic Science

The world of forensic science is changing at a very fast pace. This is in terms of the provision of forensic science services, the development of technologies and knowledge and the interpretation of analytical and other data as it is applied within forensic practice. Practicing forensic scientists are constantly striving to deliver the very best for the judicial process and as such need a reliable and robust knowledge base within their diverse disciplines. It is hoped that this book series will be a valuable resource for forensic science practitioners in the pursuit of such knowledge.

The Forensic Science Society is the professional body for forensic practitioners in the United Kingdom. The Society was founded in 1959 and gained professional body status in 2006. The Society is committed to the development of the forensic sciences in all of its many facets and in particular to the delivery of highly professional and worthwhile publications within these disciplines through ventures such as this book series.

Dr. Niamh Nic Da é id Series editor.

Acknowledgements

In writing the second edition of this book I have been assisted by more people than I could begin to recount. Of these, a few deserve special mention.

Quenten Ford not only for his invaluable help in formulating the outline of the original book, but also for his assistance in correcting the many typos that crept in.

Barbara Scott for her help with the statistics and various formulae used in both editions.

Dr James Hamby, Evan Thompson and Chris Trumble for all their help and advice in so many ways.

And last, but not least Barbara, Edward and Emily, my wife and children, for all their support and understanding without which I could never have written this book.

Foreword

tant work undertaken by the Analystits responsibility and importance lies in
at law, either civil or criminalFor these reasons the work demands the greatest
and, lastly, a suffi ciency of time

Medico - legal analysis forms, perhaps beyond all other branches, the most importhe fact that, as the term itself suggests, questions of health, or even of life or death are involved, and secondly, that the work performed will usually result in an action skill and experience that can be brought to bear upon it the best instrumental equipment that can be procured, the utmost patience, the most rigidly exact work,

Stirring and eminently appropriate sentiments which would do justice to any modern forensic laboratory administrator. The fact that these words were spoken by E.R. Dovey, Government Analyst of Hong Kong, in an address in 1917, is both a remarkable testament to that scientist and a realization that even 80 years ago, the profession he represented fully appreciated the vital role that forensic science can play in the justice system.

Incredible advances have been made in the sciences over the last few decades, and modern forensic laboratories are now staffed by teams of specialists, all experts in their own particular fi elds. The days are past when a forensic scientist appeared in the witness box one day as an expert in blood grouping, the next as a questioned document examiner and a third day as a suspicious fi re investigator. Such ‘ generalists ’ do still present themselves from time to time, but informed courts now afford them a level of credence bordering on ridicule, and rightly so!

Increasing specialization and sophistication of scientifi c method has, however, widened the gulf of knowledge between the scientist, the lawyer and the jury. With a poor level of scientifi c literacy in the population at large, frequent criticism of the capacity of scientists to express themselves intelligibly to a lay xiv FOREWORD audience, and a predominance of barristers who are unable or unwilling to help bridge the comprehension gap, that gulf is in danger of widening further.

The Select Committee on Science and Technology (House of Lords 5th Report 1992/3 ) has constructively, and to some, controversially, pointed the way forward with recommendations for pre - trial conferences between counsel and own experts as a norm rather than an occasion; pre - trial review between experts of both sides to defi ne disagreements; encouragement for concluding statements by experts before leaving the witness box; increasing use of visual aids; and fi nally, for forensic science to feature more prominently in a lawyer ’ s training.

fi eld

To satisfy the last recommendation, however, there is a need for instructional and informational textbooks on the specialist areas of the forensic sciences written with the practising criminal lawyer in mind, which bridge the gap between the handbooks for the expert and a ‘ good read ’ for the lay reader of scientifi c bent. It is to be hoped that this book fi lls that purpose in the ballistics

BRYCE N. DAILLY BSc, PhD, JP Government Chemist, Hong Kong, (retired)

1 Firearms

1.1 A Brief History of Firearms

1.1.1 Early h and c annons

The earliest type of handgun was simply a small cannon of wrought iron or bronze, fi tted to a frame or stock with metal bands or leather thongs. These weapons were loaded from the muzzle end of the barrel with powder, wad and ball. A small hole at the breech end of the barrel, the touch hole , was provided with a pan into which a priming charge of powder was placed. On igniting this priming charge, either with a hot iron or lighted match, fi re fl ashed through the touch hole and into the main powder charge to discharge the weapon.

These early weapons could have been little more than psychological deterrents being clumsy, slow to fi re and diffi cult to aim. In addition, rain or damp weather had an adverse effect on the priming charge making it impossible to ignite.

Their fi rst reported use is diffi cult to ascertain with any degree of certainty, but a number of instances are reported in Spain between 1247 and 1311. In the records for the Belgian city of Ghent, there are confi rmed sightings of the use of hand cannons in Germany in 1313. One of the earliest illustrations concerning the use of hand cannons appears in the fi fteenth century fresco in the Palazzo Publico, Sienna, Italy.

The fi rst recorded use of the hand cannon as a cavalry weapon appeared in 1449 in the manuscripts of Marianus Jacobus. This shows a mounted soldier with such a weapon resting on a fork attached to the pommel of the saddle. It is interesting to note that the use of the saddle pommel to either carry or aim

Handbook of Firearms and Ballistics: Second Edition Brian J. Heard © 2008 John Wiley & Sons, Ltd.

2 CH1 FIREARMS

the hand guns could be the origin of the word ‘ pistol ’ , the early cavalry word for the pommel of the saddle being ‘ pistallo ’ .

was ignited, all the barrels discharged at once

Combinations of the battle axe and hand cannon were used in the sixteenth century, and a number of these can be found in the Tower of London. One English development of this consisted of a large mace, the head of which had a number of separate barrels. At the rear of the barrels, a concealed chamber containing priming powder led to all the barrels. When the priming compound

1.1.2 The m atchlock

This was really the fi rst major advance in pistols as it enabled the weapon to be fi red in one hand and also gave some opportunity to aim it as well.

The construction of the matchlock was exactly the same as the hand cannon in that it was muzzle loaded and had a touch hole covered with a priming charge. The only difference was that the match , a slow - burning piece of cord used to ignite the priming charge, was held in a curved hook screwed to the side of the frame. To fi re the gun, the hook was merely pushed forward to drop

Figure 1.1 Early hand cannon.

A BRIEF HISTORY OF FIREARMS 3

the burning end of the match into the priming charge. As these weapons became more sophisticated, the curved hook was embellished and took on the form of a snake and became known as the weapon ’ s serpentine .

(Figure 1.2 )

Eventually, the tail of the serpentine was lengthened and became the forerunner of the modern trigger. Further refi nements included the use of a spring to hold the head back into a safety position. The fi nal refi nement consisted of a system whereby when the tail of the serpentine was pulled, the match rapidly fell into the priming compound under spring pressure. This refi nement, a true trigger mechanism, provided better ignition and assisted aiming considerably

It was during the era of the matchlock that reliable English records appeared, and it is recorded that Henry VIII, who reigned from 1509 until 1547, armed many of his cavalry with matchlocks. The fi rst true revolving weapon is also attributed to the period of Henry VIII and is on show in the Tower of London. This weapon consists of a single barrel and four revolving chambers. Each chamber is provided with its own touch hole and priming chamber which has a sliding cover. Although the actual lock is missing from the Tower of London weapon, its construction strongly suggests a single matchlock was used.

(Parte 1 de 5)

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