Death's Acre Read online

  A handful of my braver anthropology students gathered around. The fall term had started only hours before—it was the day after Labor Day—and already things were getting lively. Despite the gruesomeness of it all, studying a freshly unearthed murder victim was a unique learning opportunity, one that few anthropology students—and not all that many professors—ever receive.

  When you examine a body in a forensic case, I told the students, the ultimate goal is to make a positive identification. If possible, you also want to determine the cause of death (technically, only medical examiners can determine cause of death; we anthropologists call things like stab wounds and gunshots “manner of death”).

  But before you can tell who someone was and how they died—and you won’t always be able to tell—you start with the Big Four: sex, race, age, and stature.

  Whenever I examine human remains, I start by laying out the body or the bones face up, in anatomical order. In this case, that didn’t take long: The KBI had brought me just three pieces—a femur, a mandible (lower jaw), and a skull. Back in 1962, anthropologists were seldom brought to crime scenes to help excavate or recover remains; instead, police did the excavations as best they could (sometimes carefully, often clumsily), then brought over the skull, as in this case, or maybe a broken bone or a cut rib, and asked about whatever was puzzling them. It was rather like asking a mechanic to diagnose your car’s backfiring by taking him just your carburetor or alternator instead of letting him inspect the whole car, but that’s how things were done in those days. Fortunately, over the years I developed close working relationships with police, so increasingly I was called to crime scenes to recover remains as soon as they were found.

  As the students leaned in for a closer look—some of them holding their breath against the smell—we studied the femur, which still had quite a lot of tissue on it. From the angle of the femoral head (the “ball” that fits into the hip joint’s socket) and the lower articulating surface, where the femur joins the tibia to form the knee, I could tell we were holding the right femur. I laid it on the grass, adjoining an imaginary hipbone. Somewhere in between I mentally pictured a pelvis, a spinal column, two arms, and the rib cage. At the top of the imaginary spine I laid the head and mandible.

  The face was gone. Leering up at us from the grass was a greasy, stained skull with rotting patches of skin and muscle at the sides and back of the head. For a bone man like me (this was years before the term forensic anthropologist was coined), the absence of flesh on the face would actually simplify our task.

  Here’s why: A corpse’s skin can be deceptive. If a body is bloated, the facial tissues can swell, making it more difficult to discern the person’s gender. If the genitals are missing—because of dismemberment, decomposition, putrefaction, or animal feeding—or the soft tissue is badly decomposed, the shapes of the bones themselves will offer the most reliable information.

  This particular skull was small, which immediately suggested either a child or a woman. The mouth was narrow and the chin was pointed—additional features characteristic of a woman. The forehead was gracile—smooth or streamlined, particularly the forehead and the ridge above the eyebrows: a textbook example of a woman’s skull, I told the students.

  “You’ve probably seen cartoons of big, hulking Neanderthal cavemen,” I said. “The men have these massive brow ridges, so that when another caveman clubs them with a woolly mammoth femur, it doesn’t hurt.” They laughed at that; over the years I’ve found that humor helps students learn, so I always look for opportunities to throw in jokes that will reinforce what I’m explaining. “I’m not saying that we men have failed to evolve in the last twenty thousand years, but a modern male skull looks a whole lot more like a Neanderthal’s than a modern female skull does.”

  Holding the skull up so they could see it better (and smell it better, too, unfortunately), I showed them the brow ridge above the eyes. Lacking the massive ridge of the male, a woman’s skull has sharp edges where the eye orbits, or sockets, are set beneath the forehead. Finally, turning the head around, I showed them the base of the skull—the occipital bone—where men have a bony bump called the external occipital protuberance. This skull didn’t; clearly this was not a manly man.

  “But how can you tell for sure,” I asked the students, “whether this was an adult woman or a twelve-year-old boy?”

  One of the students hazarded a guess: “The teeth?”

  “That’s right,” I said, “the teeth.”

  Our mystery victim had a full set of teeth—thirty, including the upper pair of third molars, or wisdom teeth, though not the lower pair. One evolutionary change we humans are undergoing as we’ve given up gnawing on animal bones is the gradual loss of our third molars. Some people’s wisdom teeth never erupt; they’re like a seed that never germinates. So, finding a skull in which the third molars haven’t erupted, I explained, doesn’t necessarily mean that the person was not yet an adult. However, if the third molars have erupted, I stressed, it’s virtually certain that the individual was eighteen or older. In this case, then, I was pretty sure we were looking at an adult woman.

  The best way to confirm that, I added, would be to examine the pelvis. It was a shame we didn’t have it.

  The adult pelvis is a complexly engineered structure resulting from the union of three rugged bones: the sacrum, at the base of the spinal column, and the two hipbones, the right innominate bone and the left innominate. (The term innominate, which translates as “nameless” or “unnamable” bone, is a comment on its odd shape: Viewed from the front, the hipbones flare out like the ears of an angry elephant; underneath those flaring, bony ears are two knobs pierced by openings like empty eye sockets; in front, two prongs of bone converge like tusks grown badly awry.)

  The sacrum acts as a weight distributor, splitting the weight from a single column, the spine, into two columns, the legs, by way of the right innominate and the left innominate. But the innominate itself is a complicated structure, somewhat analogous to the cranium, which is also formed by the fusion of multiple bones.

  Before puberty, each innominate bone consists of three separate bones: the ilium, the ischium, and the pubis. The ilium is the highest, broadest part of the hipbone; its crest is what flares out like elephant ears just below the waist. The ischium is the bony structure you can feel yourself sitting on, if you wiggle your butt on a hard, wooden chair. (Some of us have a hard time feeling anything bony inside that big blob of fatty tissue, but it’s there nonetheless.) The pubis is the bone that spans the front of the abdomen, about four inches or so below the navel.

  At puberty the pelvis gets interesting in many ways, including skeletally. To allow passage of a baby’s head during childbirth, the female’s hipbone gradually broadens and the pubic bone gets longer, angling farther forward to form more of an arch for the birth canal.

  Because the male’s pelvis is markedly narrower, his femurs hang roughly straight down below his hipbones. In an adult female the femurs incline slightly inward beneath the hips. Not surprisingly, this difference in pelvic and femur geometry translates into some scientifically observable and aesthetically pleasing differences in the way men and women sit, stand, and walk.

  In the case of our recently unearthed murder victim, then, having the pelvis would have easily confirmed that the skull was a woman’s.

  The pelvis would also have told us more about our victim’s age. Like the sutures in the skull, the joint at the body’s midline where the left pubis meets the right pubis—called the pubic symphysis—is an excellent yardstick for measuring age. From late adolescence through about age fifty or so, the bony face of the pubic symphysis undergoes a gradual, consistent set of changes, which were first studied and cataloged more than eighty years ago: Corrugated or bumpy during a female’s late teens, the pubic symphysis smoothes out during the twenties and thirties; by age forty or so, its face begins to erode and acquires a porous, spongy look. Con
sidered along with other skeletal features such as teeth, cranial sutures, and the degree to which the ends of clavicles (collarbones) have fused to their shafts, the pubic symphysis allows an anthropologist to estimate age with remarkable accuracy—often within a year or two of the victim’s actual age.

  For determining race, though, we had everything we needed in the skull. I directed the students’ attention again to the woman’s mouth. Her teeth jutted sharply forward; so did her jawbones in the region where the teeth were rooted. It’s a trait called prognathism (from ancient Greek, meaning literally “forward jaw”); even novice anthropologists can readily recognize it as one of the hallmarks of Negroid skulls.

  There’s an easy test for prognathism, I told them, and I demonstrated with the skull in my hand. Take a pencil and press one end between your upper lip and the base of your nose. Holding that end in place as a pivot point, swivel the pencil downward. If it contacts the lips and teeth but can’t touch the chin, your skull is prognathic and probably Negroid; if it can touch both the base of the nasal opening and the tip of the chin, your skull is orthognathic (flat) and probably Caucasoid.

  Our skull passed the pencil test for prognathism with flying colors; her jaw morphology was a textbook example of Negroid structure. The teeth themselves were further confirmation: The tops of her molars were rugged and bumpy—crenulated, anthropologists call it—unlike the smoother cusps of Caucasoid teeth.

  A word about race: In recent years, the very concept of distinct races has come under attack. Race is merely a cultural construct, says one recent school of thought, not an objective physical or genetic feature. On the one hand, it can be useful to question and rethink our notions of what race means; on the other hand, I’ve examined tens of thousands of skulls over the course of nearly half a century, and their features—visually distinct, numerically measurable, and statistically graphable—correspond quite consistently to three main groupings: Negroid, Caucasoid, and Mongoloid. (Anthropologically, Mongoloid refers to Asian, Eskimo, or Native American ancestry, not Down’s syndrome.) As the world’s peoples increasingly mingle, traditional racial distinctions and labels may eventually blur and even disappear, but in the meantime I’ll hang on to them, because they help me identify the dead and they help police solve murders.

  By now, the students had absorbed enough knowledge and enough odor for one hot afternoon. I returned the skull and femur to their plastic bag, closed the box, and took it to my car. Unlike the KBI agents, I put the box in the trunk. I wasn’t quite willing to put the remains in the passenger compartment, but I was willing to bring them into our kitchen and simmer them on Ann’s stove.

  To refine my estimate of age and to gauge the woman’s stature, I needed to remove the remaining tissue from the bones. Short of leaving the skull and femur outdoors and allowing insects and scavengers to pick the bones clean—a slow process, and one that could mean losing the femur or mandible to some scavenging buzzard or coyote—the only good way to clean the bones was to simmer them in a covered steam vat for the better part of a day, then scrub off the softened tissue with a toothbrush (not my own personal one, mind you).

  Ann was a nutrition scientist; she took her cooking, and her kitchen, very seriously. Needless to say, she wasn’t thrilled when she arrived home to the stench of cooking flesh and found a decaying human skull and femur simmering in her eight-quart kettle. She’d walked in on this more than once: Part of the University of Kansas anthropology department, including my office, was housed in the Museum of Natural History; it was a grand old building, but it was built to house old, dry bones, not process fresh, tissue-covered ones. As a scientist herself, Ann realized I had to get the work done any way I could. Marriage survives on compromise, and we had hammered out some unorthodox but workable ones: She tolerated my occasional use of her stove for processing remains, but her pots and pans were strictly off limits—I had to provide my own.

  It’s true what they say: A watched pot never boils. However, an unattended one—at least if it’s filled with human bones and decomposing flesh—swiftly bubbles over. I left my post at the stove just long enough to go to the bathroom; when I returned, a froth of water, brain soup, and other foul-smelling components was pouring over the rim and seeping into every recess of Ann’s stove. It would never be the same. From that day on, moments after a burner or the oven was switched on, that same foul odor would curl upward and fill the kitchen. Exercising my incredible powers of scientific deduction, I swiftly deduced that daily reminders of my lapse at the stove might not be conducive to marital harmony, so in very short order, Ann was the proud owner of a new kitchen stove.

  Meanwhile, I had scrubbed the bones and set them out in the early-September sunshine to dry. Scrubbed clean of all its soft tissue, the skull gleamed with a smooth, ivorylike sheen—another characteristic of Negroid skulls, whose bone is denser than Caucasoid skulls. The mouth’s prognathism was even more pronounced, now that there was no tissue altering the skull’s contours. The nasal opening was broad, with vertical “guttering” in the upper jaw—distinctly different from the horizontal sill or “dam” at the base of a Caucasian’s nasal opening. (The broad, unimpeded nasal opening in the Negroid skull evolved to promote rapid air exchange and cooling in hot climates; the narrower opening and nasal dam in Caucasoids evolved to keep cold European air from flowing too rapidly into the lungs.)

  So by now I knew these bones were from a Negro female and I knew she was an adult. But was she eighteen or was she eighty? To find out, I looked to the cranial sutures.

  Most people think of the cranium as a single dome of bone, and if you run your hands over the top of your head, it certainly feels like one piece. In reality, though, the cranial vault is a complex assembly of seven separate bones: the frontal bone, or forehead; a pair of parietal bones, which forms the skull’s upper sides and rear; the temporal bones, low on either side; the sphenoid, which forms the floor and part of the sides, and the occipital bone, the skull’s heavy back and base, which rests atop the first cervical vertebra and channels the spinal cord into the neck. (For a labeled diagram of the skull, see Appendix I, “Bones of the Human Skeleton.”)

  The joints where the cranium’s seven bones meet are called sutures. The name refers to their appearance: They have a serrated or zigzag look, like the ragged stitches holding together Dr. Frankenstein’s monster. When we’re born, the joints are actually formed of cartilage, but as we age, the cartilage ossifies (turns to bone) and the sutures smooth over, all but disappearing by old age in many cases.

  This woman’s coronal cranial suture—the one running across the top of her head—had begun to fuse; that meant she must have been at least twenty-eight, because generally that joint is one of the last to fuse. But the fact that it was only partially fused indicated that she was probably not far past thirty—probably thirty-four at the oldest, I estimated.

  So far so good: I knew three of the Big Four—sex, race, and age. That left only stature. For centuries, artists and scientists have noticed that although people’s height or stature can vary enormously, their proportions—the ratio of leg length to total stature, for instance—are all pretty much the same. There’s a famous illustration in Leonardo da Vinci’s notebooks showing a nude man drawn within a circle and a square; he’s drawn with four arms (one pair stretched out to the side horizontally, the other pair elevated so the fingertips are at the same height as the top of his head) and four legs (one pair with the feet together, the other pair with the feet spread several feet apart). In his trademark mirror-image script below the illustration, Leonardo adds these observations on human proportion developed by the architect Vitruvius: “The length of a man’s outspread arms is equal to his height. . . . The greatest width of the shoulders contains in itself the fourth part of man. From the elbow to the tip of the hand will be the fifth part of a man; and from the elbow to the angle of the armpit will be the eighth part of man. The whole hand will be the tenth part of the
man.”*

  In the 1950s anthropologist Mildred Trotter and statistician Goldine Gleser took that age-old notion of proportionality and conducted extensive skeletal research to refine its accuracy. After measuring hundreds of skeletons, Trotter and Gleser devised formulas that could extrapolate stature from the length of any of the body’s so-called long bones—the bones of the arms (humerus, radius, or ulna) or legs (femur, tibia, or fibula). The best results come from measuring the femur, the thighbone; that’s probably why the KBI brought me a femur.

  Placing the bone on an osteometric board—a sliding wooden gizmo that resembles a pair of bookends joined by a yardstick—I measured its length at 47.2 centimeters. Then I plugged that number into Trotter and Gleser’s formula for Negroid females: (47.2 × 2.28) + 59.76. The resulting number, 167.38, was her stature in centimeters. Translating from metric measurements to English units told me that the woman was about five feet six inches, give or take an inch.

  So now I knew all four: sex, female; race, black; age, thirty to thirty-four; height, five feet six inches. The next question would be harder to answer definitively: Who was she? Normally, when a skull comes in with a full set of teeth, there’s a reasonably good chance of making a positive identification. The trick is to match preexisting dental X rays with the corpse’s fillings or bridgework or other unique features in the shape, structure, or arrangement of the teeth. Of course, to do that, you’ve got to lay your hands on the dental X rays of missing persons who match the age range, sex, and race of your corpse. That isn’t always possible, but you’d be surprised how often a dentist is able to provide the records needed to cinch an identification.

  In this case, though, there was a problem: This woman’s teeth showed no signs of any dental work. Lord knows, she could have used some dental work: She had large cavities in two of her lower teeth and in five of her upper teeth, and smaller cavities in most of her other teeth. Worse, one of her upper wisdom teeth had abscessed. The lack of dental care meant she was probably poor; the fact that she’d managed to hang on to her teeth so far, and had been able to withstand the pain of an abscess, suggested that she was one tough cookie. One other feature of her dentition was striking: When I fitted her mandible to her skull, I couldn’t quite get her lower jaw to line up beneath her upper jaw; the mandible skewed about a quarter-inch to the right, giving her a slight but distinctive crossbite that would have shown up whenever she flashed a big smile.