These cases represent years of work by many dedicated men and women: judges, coroners, prosecutors, defense attorneys, investigators, forensic pathologists, and other forensic scientists with whom I have had the privilege to work during my career. To simplify the presentation, some characters combine two or more individuals; at least one character usually incorporates my own point of view. Names have been changed—the focus is to show method, not to develop characters. When a case remains legally “open,” some details, including names and places, have been altered. However, the essential features of each case regarding the thinking behind forensic science, forensic medicine, and detection remain intact. Sherlock Holmes comes closest to illustrating this thinking in Doyle’s popular detective stories. Doyle, a physician, patterned his hero after Joseph Bell, M.D., Doyle’s professor of medicine at Edinburgh. The logic Holmes employed as the most famous solitary scientific sleuth of fiction survives in the daily casework of detectives, forensic scientists, and medical examiners. It helps us recognize clues, sort evidence from coincidence, distinguish truth f rom falsehood, and evaluate guilt or innocence. This logic of explanation soon became the focus of my professional interest as both a philosopher and as a member of various death investigation teams over the years.

As an enthusiastic young fan of Doyle’s Holmes, I planned a career as a physician, hoping to develop the ability to observe a patient’s symptoms, and magically, to diagnose the underlying disease. My father, an orthopedic surgeon, stimulated my interest in medicine and amazed me by reading X-rays, deciphering mysterious ghosts of injury and explaining the likely outcomes of treatment. My mother, an artist, nurtured my empathetic powers and sharpened my eye for detail.

But I soon found that premedical study offered little to help me investigate the intrigues of medical diagnosis. I turned to philosophy, the only discipline I found that expressed an interest in thinking about thinking itself, and to art, the field I chose to help me train as a careful observer.

Throughout my training, this interest in medical diagnosis and an eventual disinterest in medical treatment led me from clinical medicine to death investigation. I never have lost my fascination with logical methods applied to decipher chaotic death scenes, and to derive orderly explanations from their jumbled clues, and that interest accompanies me while I work death cases as an investigator. I have followed this interest for 20 years, studying and applying logic and the forensic sciences as an investigator involved with each of the 10 cases described in the following chapters.

These cases come from my experience as one member of a larger death investigation team working together to explain a death. I dissect each investigation from my own philosophical viewpoint. Unlike the rigid rules used to define modern formal logic, the methods of dead reckoning do not reduce to a set of procedures to be followed blindly.

Some philosophers of science have attempted to supply an account of scientific reasoning as a middle ground between overly rigid rules and the methodological equivalent of a birthday celebration at a McDonald’s Playland. We seek a philosophically robust distinction between science and pseudoscience; between methodically defensible explanations, and utter nonsense. Useful dead reckoning must be distinguished from useless random guessing which ignores relevant signs, even when such random guesses coincidentally reach the right answer.

The specific challenges in these 10 cases reveal both the strengths and weaknesses of applied logical methods. The powerful abstractions of science often hang helplessly from a web spun of ordinary circumstance. At some point, under some of these circumstances, even the fictional master of the method, Sherlock Holmes, may have to admit defeat.

Holmes, like his contemporary nonfiction counterparts, operates with what 19th- and early 20th-century American philosopher Charles Sanders Peirce [pronounced purse] calls the logic of abduction. Abduction provides a method of reasoning from presented signs to their probable explanations. Acloak of interpretive uncertainty shadows both the method and its result. As in navigating by dead reckoning, correctly reading the signs forms the heart of the process. This abductive process, displayed by Doyle through Holmes’ uncanny ability to read the signs correctly, has its limits.

Each chapter’s case approach exhibits the logical methods of the forensic sciences, forensic medicine, and detection in specific contexts facing specific challenges. Some challenges provide insurmountable limits. If Peirce is right, such practical contexts are required for any accurate glimpse of the logic of a scientific method having dead reckoning at its center. Without the framework of real cases, the search for scientific method degenerates into the logically impossible quest for a non-existent abstraction, akin to attempts to view form without shape.

The powers of observation exercised in reading the signs, identifying them as clues, and reasoning from them to the best explanation, develop slowly through experience and training. The ability to determine the number of blows striking a bludgeoning victim from blood spatter, or to estimate time of death from decomposition and ambient conditions cannot be learned from treatises on fluid mechanics, biochemistry, or microbiology. Such abilities come from paying attention to the details, from seeing and doing while thinking, from learning when and how to trust one’s own eyes through the fog of subterfuge, deceit, and coincidence. Sometimes familiar fictional characters other than Sherlock Holmes help model the process.

As Batman and Robin hang from their “Bat Ropes,” walking up the side of a warehouse in search of the Joker, Riddler, Penguin, and Catwoman, Robin breaks the determined silence. “Think, Batman, with four super crooks in weird outfits hanging around, it’s amazing someone hasn’t reported them to the police.” Batman explains by saying, “It’s a low-brow neighborhood, Robin, full of saloons. Citizens attribute any curious sights to alcoholic delusions.” Robin replies, “Golly, drink is a dirty thing—I’d rather die than be unable to trust my own eyes!” The 10 cases in the following chapters each display elements of learning how to trust one’s own eyes, learning how to navigate the turbulent and ancient sea of clashing opinion and hazardous belief, noticeably rougher in modern science’s powerful wake.
(from Dead Reckoning: The art of forensic detection, Jon J. Nordby)