It’s impossible to cover all of forensic science over the course of six modules even at an introductory level. And we have not tried to do that. Instead, we tailored the class to provide you with the ability to understand the basics behind any forensic situation that you encounter, whether as a bystander viewing news reports or fictional media, or as a professional in a related discipline. For example, a science teacher or a police officer. We focused on forensic science in the sense of the scientific investigation of crime. And began where the crime begins, at the scene of the reported incident. In this case, a murder.
Module one dealt with the basic principles of scene examination with a narrative that took us from the reporting of the incident to the preliminary evaluation by the investigators and crime scene examiners. Any initial scene investigation consists largely of the exercising of professional judgement in interpretation of the nature and disposition of physical items created or altered in the course of committing the crime. As the investigation progresses, naked eye observation becomes supported by increasingly complex procedures. But the thread of interpretation of making the things at the scene tell the story of what happened remains. That is why the principles presented and the CoPRRR mnemonic matter so much.
A scene that is not controlled, preserved, and recorded, allowing recovery of the items that will permit an accurate reconstruction of events to be made is as useless as a bad research experiment that has no controls, sketchy or incorrect notes, and data that is corrupted by contamination or loss. The increasing technical complexity of the investigation was reflected in the content of subsequent weeks, progressing from the development of latent, hidden, or concealed finger marks to DNA, the comparison of tool marks and other impression evidence through to the synthesis and identification of illicit drugs. Forensic science increasingly makes use of advances in technology applying these to criminal investigations. However, this must be within the context of fundamental scientific principles.
The science in DNA analysis lay in the identification of the molecular genetics and the development of the technology to permit identification of the profiles. By the time we get to forensic DNA, we are almost to dealing with a black box. Samples are introduced at one end of a computer controlled machine, and the answers come out the other end. Forensic science is likewise somewhat parasitic in applying technology to the identification of drugs and their synthetic precursors. The picture being painted here is that using the fruits of scientific discoveries– perhaps by applying cutting edge technology– does not in itself make an activity scientific.
To address the question, what is forensic science, we need to step aside from the murder by the loch and think about what science itself is. The work science is derived from the latin, scientia. Which in turn, is derived from the verb sciri, meaning “to know.” Literally therefore, science is about knowledge. But over time, the meaning has become more specific. And now refers to knowledge about the natural world. The word forensic also has its origins in Latin. Being derived from forensis, which means “in open court.” With forensis coming from forum, which was a public square where matters were argued and adjudicated in ancient Roman cities.
Some of the ancient Roman and Greek philosophers developed a logical structure to use in making their case. It was asking and answering the questions quis, quid, quando, ubi, quare, quem ad modum, and quibus adminiculis. Or who, what, when, where, why and how, in what way and by what means. These are our six W’s. And as we saw in week one, they’re not just interrogatives, but are questions that demand a factual answer. Which is what gives them their power. They were the tools used by the rhetors to further knowledge and understanding. But we are still far away from what we would now recognise as science.
For example, the same culture that gave us the six Ws also gives a blueprint of nature in which everything was made from combinations of the four elements– fire, air, water, and earth. It was not until the 15th and 16th centuries that the foundations for the body of knowledge that we now call science were established. Those foundations gave us what we know as the scientific method. Which is a process that begins with observations, procedes to developing a hypothesis to explain them, inductive reasoning, and then moves to the absolutely critical element of testing the validity of that hypothesis. If our hypothesis is a good one, we can apply deductive reasoning to predict something.
And then, look and see if the predicted event does indeed occur. If it does, our hypothesis lives to see another day and another test. If it does not, then the hypothesis must be revised or rejected. The cycle of observation, induction, hypothesis formation, deduction, testing, revision or rejection of the hypothesis is absolutely fundamental to science. To learn a bit more about the scientific method, have a look at the materials in the resources section. For now, there are two overriding considerations. The integrity of the process depends on the integrity of the testing. It should be designed as a rigorous challenge to the hypothesis.
No single experiment can ever prove a hypothesis is correct, only confirm that it remains acceptable in the light of current knowledge. There is considerable debate as to whether what we call forensic science is indeed a legitimate branch of science. The case for no ranges from the view of highly qualified physicists, chemists, and biologists who suggest that forensic science reflects the milieu within which one or more these fundamental sciences is practised, rather than any intrinsic properties. To the opposite extreme with the observation that many practitioners who are obviously doing things forensic do not possess any formal scientific qualification. A police officer conducting the examination of firearms, for example.
However, if we go back to week one and choose the work of the crime scene examiner as an example, what forensic scientists do when done properly is very much pure science in the sense that it is faithful to the scientific method. Each case is a new experiment beginning with a unique set of observations, the incident, and the crime scene. And progressing through rigorous testing until the final explanation is captured in the submitted report.