Historically, forensic science did not originate from a culture of research; rather, academicians and medical specialists applied their knowledge of basic science to questions of criminal activity.1 This has led to those involved in non-forensic academic circles to sometimes view forensic science as “only an applied science” or a lesser area of study.
In these academicians’ view, because forensic science is not a basic science — seeking knowledge for the sake of knowledge alone — they fail to see its value as discipline. On the forensic side, some practitioners feel that academicians misunderstand and misapply forensic science because they have not worked in a forensic laboratory (“Those who can, do; those who can’t, teach.”). We, along with many others, think these two viewpoints must change.
For example, assume that someone asks, “What is the error rate for fingerprints?” The answer from certain quarters is, “The error rate of the method is zero.” Any scientist knows that no method in science has a zero-error rate — it is simply not possible. Every measurement has some inherent error; that is the entire reason for statistics. In any series of measurements, each of those measurements will be off by some amount. Knowing how much they are off and in what direction they are off gives a better sense of what the true measurement is. By saying, “There is no error in this,” you are willfully blinding yourself to the nature of science and to what needs to be done for that discipline. “No error” is not an empirically provable answer and, therefore, outside the realm of science. This answer is of a legal mindset, not a scientific one. Undoubtedly, forensic fingerprinting can be conducted as a science and an error rate can be deduced, as several research efforts suggest.2 When a forensic expert says to an academic, “You could not possibly understand the subtleties or what I do,” a red flag should fly. If a method is scientific, it has to be able to be learned, communicated, and replicated. These are some of the hallmarks of science.3
Conversely, when academicians look down their noses at an applied science, they ignore the potential that forensic science offers to research and teaching.4 Forensic scientists historically have been too busy working cases to conduct research — that has not been their jurisdictional mandate — although it is their scientific mandate. The fundamental principles and theories that allow forensic scientists to perform their work have not been made explicit. This, however, does not mean they do not exist. As Marcel Proust said, methodology, when made explicit in writing, is like a price tag on a suit of clothing. Indeed, our discipline’s philosophy is inherent in every measurement we take. The physicist P. W. Bridgman stated:
In general we mean by any concept nothing more than a set of operations; the concept is synonymous with the corresponding set of operations.5 (p. 5, original italics)
If you take a measurement, you have to have a theory of some sort; otherwise, how would you know what measurement to take? For example, if you’re measuring length, some reason or some principle tells you length is important. And if that length is measured in millimeters, then scale is important, as opposed to doing it in inches, yards, or miles.
As forensic scientists, we have not had the time or the leisure to tease out the philosophy or theories and make them apparent; concepts, such as individualization6 (a set with one and only one member as a source) and exchange7 (when two objects come into contact, information is exchanged), point the way. Academia has done this with their theories, but that is part of what they do: knowledge for the sake of knowledge. Forensic scientists need to be more open about examining their discipline and their methods. They should allow academicians to point out a few holes that could be patched. By the same token, academicians need to roam out of their “ivory towers” and talk with forensic practitioners so they will be able to understand what it is that they do. A fundamental difference exists between what forensic scientists do and what chemists and biologists do. The two sides need to step across that artificial line. It is interesting to note that in its early history, chemistry suffered the same sort of bias as an applied science.8