II. Primary Areas of Forensic Science
For many Americans, the word forensics evokes a cascade of vibrant imagery that entails crime and intrigue. It is a buzzword for DNA, bite marks, bullet wounds, fingerprints, autopsy, gore, death investigations, semen stains, and rape kits. This, however, is only a small part of a much larger picture. Forensics itself is extremely broad—it is the application of the scientific method to assist the law. This can mean almost anything— accountants who perform analysis to assist the courts are forensic accountants; computer enthusiasts who hack into the hard drives of sexual predators are forensic computer technicians; physical anthropologists who study bones in a legal investigation are forensic anthropologists. The field of forensics is growing, and the list becomes even longer as more divisions of labor and specialization occur. With this large influx of experts in fields that expand with technology and multitudes of new techniques, it is amazing that the courts can even keep up.
The many different disciplines that make up forensic science have been embedded in popular culture since their inception. Long before criminal investigations incorporated the use of fingerprints, document examination, blood spatter pattern analysis, gunshot trajectories, accident reconstruction, and the like, these were the topics of fiction. Most familiar to many, Sherlock Holmes and his partner, Dr. Watson, applied the scientific method and stellar detective work to solve crimes and thereby introduced these concepts to the masses. Broadly speaking, this is the definition of forensic science: applying science and technology to legal investigations, whether civil or criminal. From the “medicolegal” examination of a human body postmortem (after death) to analyzing the breath of a driver who had a few too many drinks, the reconstruction of how the Twin Towers collapsed, and the identification of unknown soldiers and civilians in battlefields in mass graves, these practices have now long been integrated into Westernized contemporary court and justice systems. Yet, it was only in recent decades that the abilities of forensic scientists have vastly expanded due to a renaissance of scientific breakthroughs. The purpose of this research paper is to give an overview of the primary areas of forensic science and to review the breakthroughs and controversies within each of its disciplines. Secondarily, this research paper provides an introduction into how the courts screen expert witnesses and concludes with a summary of important recent developments in forensic science.
II. Primary Areas of Forensic Science
Many of the foundations of forensic science are rooted in keen criminal investigative principles adjoined with analysis using the scientific method. The work of Edmond Locard is a case in point. In the early 1900s, Locard developed a simple investigative principle that has stood the test of time and is very much incorporated in today’s detective work. Basically, Locard realized that as individuals interact with others or come in contact with objects in an environment, a “cross-transfer” of microscopic and macroscopic elements will occur. A bit of a dog owner’s hair will remain on the person’s clothes and may be left at a crime scene along with some skin cells, and perhaps some of the carpet fibers at the crime scene will cling to the cuff on an individual’s pants; either way, evidence of this transfer may serve as a substantial piece of circumstantial evidence in a case. This principle, called “Locard’s exchange principle,” is at the heart of trace evidence and criminal investigations. Much of the forensic investigation performed at a crime scene, such as utilizing the exchange principle to collect and subsequently analyze evidence, is in the area of criminalistics.