The ninth edition of Criminalistics has a new look. Wider margins along with color photographs and figures have been incorporated into the book's design. A new chapter on computer forensics has been added. What has not changed is the basic aim of the book: to make the subject of forensic science comprehensible to a wide variety of readers who are or plan to be aligned with the forensic science profession, as well as to those who are curious about the subject's underpinnings. Many readers of this book have been drawn to the subject by the assortment of television shows that are based on it. Story lines depicting the crime-solving abilities of forensic scientists have excited the imagination of the general public. Perhaps we can attribute our obsession with forensic science to the yearnings of a society bent on apprehending criminals but desirous of a system of justice that ensures the correctness of its verdicts. The level of sophistication that forensic science has brought to criminal investigations is awesome. But one cannot lose sight of the fact that, once one puts aside all the drama of a forensic science case, what remains is an academic subject emphasizing logic and technology. It is to this end that the ninth edition of Criminalistics is dedicated.

Criminalistics strives to make the technology of the modern crime laboratory clear and comprehensible to the nonscientist. The nature of physical evidence is defined, and the limitations that technology and current knowledge impose on its individualization and characterization are examined. By combining case stories with applicable technology, Criminalistics endeavors to capture the pulse and fervor of forensic science investigations.

One of the constants of forensic science is how frequently its applications become front-page news. Whether the story is of sniper shootings or the tragic consequences of the terrorist attacks of September 11, 2001, forensic science is at the forefront of the public response. The horror of the terrorist attacks exemplified the critical role DNA has come to play in identifying victims of mass disaster. In this new century, the science of DNA profiling has altered the complexion of criminal investigation. DNA collected from saliva on a cup or from dandruff or sweat on a hat exemplifies the emergence of nontraditional forms of evidence collection at crime scenes. The criminal justice system is creating vast DNA data banks designed to snare the criminal who is unaware of the consequence of leaving the minutest quantity of biological material behind at a crime scene.

During the highly publicized O. J. Simpson criminal and civil trials, forensic scientists systematically placed Simpson at the crime scene through DNA analyses, hair and fiber comparisons, and footwear impressions. As millions of Americans watched the case unfold, they, in a sense, became students of forensic science. Intense media coverage of the crime-scene search and investigation, as well as the ramifications of findings of physical evidence at the crime scene, all became the subject of study, commentary, and conjecture.

For those of us who have taught forensic science in the classroom, it comes as no surprise that forensic science can grab and hold the attention of those who otherwise would have no interest in any area of science. The O. J. Simpson case amply demonstrates how intertwined criminal investigation has become with forensic science. Through nine editions, Criminalistics has striven to depict the role of the forensic scientist in the criminal justice system. The current edition builds on the content of its predecessors and updates the reader on the latest technologies available to crime laboratory personnel.

Like all facets of modern life, forensic science has been touched by the computer and the Internet. This new edition introduces the reader to basic computer technologies and concepts relied on during the forensic investigation of crimes. Retrieval of computerized information thought to be lost or erased is explored, as is the investigation of hacking incidents. Exploration of web sites particularly relevant to forensic science and criminal investigation is emphasized.

A major portion of the text centers on discussions of the common items of physical evidence encountered at crime scenes. These chapters include descriptions of forensic analysis, as well as updated techniques for the proper collection and preservation of evidence at crime scenes. Particular attention is paid to the meaning and role of probability in interpreting the evidential significance of scientifically evaluated evidence.

The implications of DNA profiling are important enough to warrant their inclusion in a separate chapter in Criminalistics. The topic of DNA is described in a manner that is comprehensible and relevant to readers who lack a scientific background. The discussion defines DNA and explains its central role in controlling the body's chemistry. Finally, the chapter explains the process of DNA typing and illustrates its application to criminal investigations through the presentation of actual case histories.

The content of Criminalistics is a reflection of the author's experience both as an active forensic scientist and as an instructor of forensic science at the college level. No prior knowledge of scientific principles or techniques is assumed of the reader. The areas of chemistry and biology relating to the analysis of physical evidence are presented with a minimum of scientific terminology and equations. The discussion involving chemistry and biology is limited to a minimum core of facts and principles that will make the subject matter comprehensible and meaningful to the nonscientist. Although it is not the intent of this book to make scientists or forensic experts of readers, it will certainly be gratifying if the book motivates some students to seek further scientific knowledge and perhaps direct their education toward a career in forensic science.

Although Criminalistics is an outgrowth of a one-semester course offered as part of a criminal justice program at many New Jersey colleges, its subject matter is not limited to the college student. Optimum utilization of crime laboratory services requires that criminal investigators have a knowledge of the techniques and capabilities of the laboratory that extends beyond any summary that may be gleaned from departmental brochures dealing with the collection and packaging of physical evidence. Only by combining a knowledge of the principles and techniques of forensic science with logic and common sense will the investigator gain comprehensive insight into the meaning and significance of physical evidence and its role in criminal investigations. Forensic science begins at the crime scene. If the investigator cannot recognize, collect, and package evidence properly, no amount of equipment or expertise will salvage the situation.

Likewise, there is a dire need to bridge the "communication gap" among lawyers, judges, and the forensic scientist. An intelligent evaluation of the scientist's data and any subsequent testimony again depends on familiarity with the underlying principles of forensic science. Too many practitioners of the law profess ignorance of the subject or attempt to gain a superficial understanding of its meaning and significance only minutes before meeting the expert witness. It is hoped that the book will provide a painless route to comprehending the nature of the science.

In order to merge theory with practice, a number of actual forensic case histories are included in the text. The intent is for these illustrations to move forensic science from the domain of the abstract into the real world of criminal investigation.