Forensic Science

by

Quentin Rossy, Joëlle Vuille

• LAST REVIEWED: 29 November 2018
• LAST MODIFIED: 29 November 2018
• DOI: 10.1093/obo/9780195396607-0143

Introduction

Any science used to assist the adjudication of a civil litigation or a criminal case becomes, de facto, a forensic science, the term forensic merely referring to the fact that it is used in a judicial context. It follows from this that the literature on forensic science is potentially unlimited. The references presented here therefore reflect the choices of the authors to restrict their overview to the general principles “governing” the field, instead of focusing on particular disciplines and their technical specificities. Resources and references to subdisciplinary fields and to forensic associations and societies can be found at Zeno’s Forensic Site and Reddy’s Forensic Page, both of which contain a large amount of categorized online resources. From the holistic perspective chosen in this article, forensic science is defined as the science that studies traces for judicial and broader policing contexts. Forensic science is a relatively new field of knowledge compared to other scientific disciplines, and most of the seminal work was published in the late 19th and early 20th centuries. Even though contemporary publications form the bulk of this review, the authors also chose to introduce the reader to classical texts, to which many scholars still refer regularly because they laid out some key principles of forensic science. Because forensic science has its roots in police work and criminal prosecutions, many publications adopt this criminological perspective. However, it should be noted that science assists triers of facts in many other fields of law, such as paternity testing, torts, patent law, and product liability. Moreover, forensic information is used in broader contexts to support the analysis of crime in an intelligence-led perspective to help better understand crime series and criminal phenomena by addressing them through their remnant, the trace.

Reasoning from Traces of Past Events

Margot 2011 defines the core object of forensic science as the “trace,” which is “a pattern, a signal, or material transferred during an event. It is the remnant (the memory) of the source (identity—who, with what?) and of the activity (what, how, when, why) that produced it” (p. 91). Edmond Locard (b. 1877–d. 1966) was one of the founders of the discipline; he built his laboratory, which is considered the world’s first police laboratory, in Lyon, France, in 1910. Locard 1920 famously defined what would later be called Locard’s exchange tenet: “The truth is that none can act with the intensity induced by criminal activities without leaving multiple traces of his path. . . The clues I want to speak of here are of two kinds: Sometimes the perpetrator leaves traces at a scene by their actions; sometimes, alternatively, he/she picked up on their clothes or their body traces of their location or presence” (translated from French in Roux, et al. 2012, p. 15, cited under Further Epistemological Considerations). Each forensic science process starts with a diagnostic phase, where traces have to be found and detected based on prior knowledge and hypothetical scenarios about the exchange. But the tenet also includes both the inference of the identity of source and inferences on activity. Indeed, the second phase of the process involves the analysis, classification, integration, and organization of traces in a structured manner to reconstruct events. This section includes classical references that describe forensic science operations and reasoning processes based on traces: Ginzburg 1979 defines a cross-disciplinary paradigm based on the deciphering of clues; Eco and Sebeok 1983 presents a semiotic discussion on abductive reasoning; DeForest, et al. 1983 promotes a general cross-disciplinary approach of cases; Inman and Rudin 2001 defines a general paradigm of the forensic science process; and Ribaux, et al. 2006 classifies elementary forms of inferences with forensic data.

• DeForest, Peter, R. Gaennslen, and Henry C. Lee. 1983. Forensic science: An introduction to criminalistics. New York: McGraw-Hill.

  An academic forensic science textbook used to broadly educate forensic generalists in various aspects and specialties of forensic science. The authors promote a global view of forensic science that helps generalists develop abilities to look at complex cases and decide what should be done.

• Eco, Umberto, and Thomas A. Sebeok, eds. 1983. The Sign of Three: Dupin, Holmes, Peirce. Advances in Semiotics. Bloomington: Indiana Univ. Press.

  The authors present an accessible semiotic discussion on the logic of Charles Sanders Peirce: abduction (in a hypothetical-deductive cycle, abduction starts from traces to develop explanations of what happens: the “Holmesian reasoning”).

• Ginzburg, C. 1979. Clues: Roots of a scientific paradigm. Theory and Society 7.3: 273–288.

  DOI: 10.1007/BF00207323

  An epistemology based on the concept of “clues” is discussed through a cross-disciplinary approach. It is based on the “deciphering of signs,” “individual cases, situations, and documents” as objects, and “knowledge that implies an inevitable margin of hazardousness of conjecture” (p. 281).

• Inman, Keith, and Norah Rudin. 2001. Principles and practices of criminalistics: The profession of forensic science. Boca Raton, FL: CRC Press.

  In this classic textbook, the authors define a forensic paradigm based on elementary forensic operations: identification, individualization, classification, and association. They also propose the principle of “divisible matter,” which states that the fracture of physical objects creates specific characteristics unique to the original item.

• Locard, Edmond. 1920. L’enquête criminelle et les méthodes scientifiques. Paris: Flammarion.

  In this book, Locard introduced what would later be called Locard’s tenet (see introduction to this section). Notably, he insisted on a transversal approach to forensic science that should not be restricted to a single trace. His principle is often oversimplified by the generalization “every contact leaves a trace,” which eludes the nature of the activity that led to the transfer.

• Margot, P. 2011. Forensic science on trial: What is the law of the land? Australian Journal of Forensic Sciences 43.2–3: 89–103.

  DOI: 10.1080/00450618.2011.555418

  A must-read article in which the author defines the object of forensic science: crime and its remnants, or “the trace.” The author discusses the principles, phases, and roles of forensic science through a historical perspective—not only for evaluative expert opinions, but also for investigative purposes to reconstruct cases, and for intelligence purposes to help understand criminal phenomena.

• Ribaux, O., S. J. Walsh, and P. Margot. 2006. The contribution of forensic science to crime analysis and investigation: Forensic intelligence. Forensic Science International 156.2–3: 171–181.

  DOI: 10.1016/j.forsciint.2004.12.028

  The authors identify and classify elementary reasoning in forensic investigations and describe the various steps that are used in the course of an investigation that relies on analogical reasoning. They notably define forensic intelligence (see Forensic Intelligence, Policing, and Criminology), describe its implementation, and present examples in the context of serious and serial crimes investigations.