About the Author(s)

Paul L. Kirk, Ph.D., is a Professor of Biochemistry and Criminalistics at the University of California in Berkeley, California.

Preface

LeMoyne Snyder in his excellent book, Homicide Investigation, includes a short chapter, “Why I Wrote This Book,” which should be required reading for all law-enforcement agents. The situation described there, involving lack of coordination, communication, and understanding, was one in which conscientious but untrained and incompetent officials did everything possible to make the crime impossible of solution, and little if anything to aid in its solution. The possible implication that this situation is characteristic only of homicides is, unfortunately, not true. Far too many crimes of all types are “investigated” as he describes. His reasons for writing the book apply equally to the writing of this one, which aims only to attack the same fundamental problem but on a broader basis.

This volume is not intended as a guide for specialists. Rather, it is written with the needs of police investigators, general criminalists in the smaller police laboratories, and students of criminalistics and police science in mind. In order to be a specialist in any phase of criminalistics, it would be necessary that the reader be far more familiar with his specialty than would be possible from this volume. It appears certain that more and more police departments will establish laboratories, and will have on their force more investigators skilled in the utilization of physical evidence. Since every crime may at times involve any given type of evidence, it is clear that the police investigator is the key man in making certain that the evidence is effectively utilized.

In the smaller department particularly, and to some extent in the larger as well, a single man may be required to handle and examine various types of evidence falling perhaps in a variety of specialties. His ability to deal with many kinds of evidence should be taken for granted just as is the physician’s ability to treat various diseases even though he does not claim to be a specialist in any one of them. Certainly the medical student is not excused from a course in obstetrics or internal medicine because he knows at an early stage in his studies that he is going to become a brain surgeon. It is equally inexcusable for an investigator to become an expert in any given type of evidence without first acquiring general and broad instruction and experience in examining other types of evidence.

It cannot be too strongly emphasized that the police investigator to whom a case is assigned is the most critical individual as regards the physical evidence, as well as the personal investigation. If he allows it to be lost, damaged, or destroyed, his case may never be proved as a result. Yet his knowledge need not be intensive or specific. It is to this individual particularly that Section I of this volume is directed in the hope that he can obtain an effective appreciation of what physical evidence is, how it may be collected and preserved, what can be done with it in the laboratory, and what it will mean when examined. It is not sufficient that he knows how to collect and preserve physical evidence. He must also understand what to collect and why it should be collected. To this end, he must understand what can be done with it and the extent to which it will benefit him to have it done. Thus he has a sound motive for intelligent cooperation with the laboratory; it is to his advantage and will also lead to the improvement of law enforcement by his department.

Section II is designed as an introduction to the field of laboratory criminalistics for the student and for the practicing criminalist whose general knowledge of the field may be inadequate. No claim is made that the material presented is exhaustive. It would obviously be beyond the scope of any single volume to cover in detail all of the useful methods of crime investigation by laboratory methods. The procedures chosen are largely those that have given good service in the author’s laboratory in investigating a wide variety of crimes. They are aimed at standardization and simplification rather than at completeness. What is gained by applying a wide variety of methods, complex methods, or time consuming methods, if the fact is established equally well by simple, rapid methods? There has been an unfortunate tendency to assume that, unless everything possible has been done in a case, nothing worth while can result. Only in criminalistics is this tendency universal. Industrial laboratories, clinical laboratories, and even consulting laboratories find it necessary to conserve time and investment by using the shortest, most efficient, and best standardized methods possible in order to operate efficiently. If the police laboratory is to earn its way, it also must standardize its procedures to cope with the large number of cases that require or should receive its attentions without at the same time being so costly as to defeat its own ends.

Several deviations from standard writing procedure have been followed throughout this volume. No text references are listed except in special instances, on the ground that they interfere with continuity of presentation. Thus, the text stands essentially alone and can be read without reference to source material. Bibliographies give adequate references for the reader who desires to pursue any given subject more thoroughly. The references also are independent and may be used without checking back to the text. For the same reason, continuity of thought, as few text references as possible are given to the figures, which also stand essentially alone, though distributed with the text material they illustrate. The most important innovation is the segregation of laboratory procedures from the material designed primarily for the police investigator. The latter may read Section I without distraction by the technical procedures of Section II; he thus avoids the disturbing effect of constantly having to skip those portions. The laboratory investigator, on the other hand, may concentrate on Section II, using Section I only for reference as to significance of evidence, its interpretation, or other similar matters.

The author is indebted directly or indirectly to many individuals or organizations, but to none so heavily as to the large group of criminalistics students, both past and present, who for years have supplemented his inadequate efforts to explore, test, investigate, and learn as much of this facinating field as is humanly possible. Particular debt of gratitude is due Mrs. Charlotte Brown, who has willingly contributed many hours of assistance in preparing this manuscript and its figures, and to D. Q. Burd and the California Division of Criminal Identification and Investigation, who have made available many excellent photographs for reproduction here. The author is under special obligation to L. J. Goin, L. W. Bradford, R. S. Greene, A. Longhetti, A. Biasotti, G. S. Boaz, R. Craig, R. Melstrom, and others for assistance at some stage of preparation of manuscript. The help of C. W. Wilson, Superintendent of the Wisconsin State Crime Laboratory, in making certain material available from that laboratory is acknowledged, as is the permission by Ordway Hilton to reproduce figures from Journal of Criminal Law and Criminology. Manufacturers who have generously contributed photographs of equipment include Microchemical Specialties Co., Bausch and Lomb, American Optical Co., E. Leitz, The Fargo Co., Erb and Gray, Graflex, Inc., Applied Research Laboratories, and Beckman Instrument Co. Last, but not least, should be acknowledged the indirect assistance of many police officers and attorneys who, because of their confidence in the author’s laboratory and students, have submitted many challenging problems that added to the quality of teaching and research and led directly to the perfection of new techniques and acquisition of new knowledge in the field of criminalistics.

P. L. K.
Berkeley, California
November, 1952