Death's Acre: Inside The Legendary Forensic Lab The Body Farm Bill Bass (howl and other poems TXT) 📖

The stature calculation told us that with her 44.4-centimeter femur, our victim had stood about five feet three inches tall.

Now we knew sex, race, age, and stature. Next came the search for evidence of the manner of death. We checked and rechecked everything. There was no sign of trauma—no fractures, cut marks, or other traces of trauma—on any of the bones we had. But we didn’t have every bone. Her feet were missing, but they probably wouldn’t have told us how she died. One other bone was missing, though, and it was potentially the single most important bone in her body. It came from the region where differential decay had raised a red flag the instant I saw the body. What we were missing was the hyoid bone from the neck—the one bone that can reliably reveal whether someone has been strangled. Floating above the larynx and below the mandible, or lower jaw, the hyoid is a thin, horseshoe-shaped bone. If you tilt your head back slightly, clasp the front of your windpipe, and wiggle your hand back and forth, you’ll probably be able to feel your hyoid moving. From its exposed position and thin structure, you’ll also understand why it’s often broken in cases of strangulation.

Given that the two more recent victims had been strangled, it seemed crucial that we find the missing hyoid. We checked the body bag carefully, in case the hyoid was somewhere at the bottom of the bag, but no luck. I called together four of my grad students. “I need you to go back out to Cahaba Lane and find that hyoid,” I told them. They looked dismayed and dubious, but I wasn’t ready to give up. Time after time I’ve been amazed at how much skeletal evidence can be recovered from a death scene, even months or years after a murder: bones, bullets, teeth, even toenails. “Start where we found her,” I told the students, “then work your way uphill to the spot where the hair mat was. It’s got to be there.” I meant that last part in more ways than one.

A few hours later they returned, triumphantly bearing the hyoid. Sure enough, up near the initial death scene, the bone had fallen out (or been plucked out by some scavenger), and then had been covered by falling leaves.

The hyoid was in three pieces, but that didn’t necessarily mean it had been broken; in some people the hyoid never fully ossifies into a single arch of bone. Instead—as in this woman’s case—the two side pieces, called the “greater horns,” are joined by cartilage to the central arch, or “body.” It was possible that the horns had been broken off, but it was also possible that the cartilage in those joints had simply decomposed. To know which was the case, I needed to look closer—much, much closer.

I took the pieces to a scanning-electron-microscope lab in the college of engineering. At a magnification of 20 ×, I thought I saw some traces of damage to the bone itself: tiny linear fractures and avulsion (literally, “pulling apart”) fractures at the surface where the cartilage had been attached. I zoomed in for a closer look. Sure enough, at 100× and 200×, the damage was unmistakable: numerous microscopic linear fractures that ended in a small region of avulsed bone.

It wasn’t much to look at, but it was crucial evidence: a telltale sign that cartilage had been ripped from this bone by some powerful force—for example, a pair of strong hands, squeezing mercilessly until the moment she ceased to struggle, ceased to breathe, ceased to live. That moment had probably come somewhere between ten and twenty days ago. I arrived at that estimate of time since death, or TSD, by correlating two sets of observations: the body’s advanced state of decomposition, and the pattern of daytime and nighttime temperatures over the past several weeks.

To narrow down the TSD, I enlisted the help of my former student, chemistry whiz Arpad Vass, who was now a research scientist at Oak Ridge National Laboratory. I sent Arpad two soil samples: one taken from beneath the victim’s body, where volatile fatty acids had soaked into the ground; the other an uncontaminated control sample taken from the hillside some fifteen feet above the death scene. In the Ramsburg case—the man shot by his wife, then buried in the crawl space beneath the house—Arpad had been handicapped by the lengthy postmortem interval. Here, though, the conditions were perfect for his technique. First, Arpad analyzed the relative concentrations of the decay products, then he factored in the temperature patterns. This time the technique worked brilliantly: Arpad’s calculations put the TSD at fourteen to seventeen days. Based on the decomp, I had put the murder sometime in the period of October 6 to 16; Arpad narrowed that window to October 12 to 15, right around the same time Patty Anderson had disappeared.

Just to be sure, the sheriff’s investigators had asked for an additional TSD estimate, for each of the bodies, from a forensic entomologist named Neal Haskell, who had done an interesting study at the Body Farm a few years before. Neal was developing a forensic technique for re-creating death scenes, in effect, by using a freshly killed pig as a stand-in for the murder victim—a “body double,” as they say in Hollywood, but of a different species. By letting nature take its course until the insects on the pig carcass matched those on the human victim, Neal hoped to be able to pinpoint time since death to within a day or two. But to know whether the pig carcasses would work as stand-ins for humans, he needed to make a head-to-head comparison of the bug activity in each species. The only place where he could do that, of course, was at UT’s Anthropology Research Facility. I was glad to have him do the study there; if the technique worked—and the study showed that it did, at least within the first couple of weeks postmortem—it could