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

in texture; that, plus the well-defined crest where the ilium fused with the sacrum, told me that she was probably somewhere between twenty-five and thirty-five. So far, at least, I hadn’t found anything that would indicate that this was not Patty Rogers, a twenty-seven-year-old white female.

Right from the outset we had all figured that these were probably Patty’s remains, but over the years I’ve learned that assumptions can cloud your thinking, leading to scientific error and personal embarrassment. I learned that lesson the hard way in the Colonel Shy case, when I misgauged the Confederate officer’s time since death by almost 113 years—my personal record for inaccuracy, by the way. I’ve also had several cases where the identity of the body turned out to be quite a surprise to homicide investigators. Over in Morgan County, a prominent local contractor disappeared from the town of Wartburg. For years afterward, every time somebody’s bones turned up, the police assumed they’d finally found him. They were particularly surprised the time I informed them that their latest find wasn’t their middle-aged male contractor at all but an eighteen-year-old female.

So as I began to inspect the shattered bones of 97-23 for some clue, I tried to keep an open mind. It was hard to keep pessimism from creeping in, though. Not a single bone was intact; much of the skull was missing; and everything was burned to a crisp. Correction: almost everything. A few vertebrae that were nestled in the bottom of the barrel had emerged largely unscathed, and so had a chunk of parietal bone, from the upper-right part of the skull. Like the other bones we’d collected, the parietal was fractured, but unlike the other shattered bones, the fracture lines of the parietal were unburned. It hadn’t been the heat of the fire, or the internal pressure as cranial fluids vaporized, that caused this fracture. Something else—some powerful external force—had shattered the skull around the time of death.

Looking at the other pieces of skull, I spotted what appeared to be telltale traces of that powerful force. The inner surfaces of three different pieces of the skull—the left parietal and two fragments of the occipital, from the base of the skull—bore traces of a grayish-black material, possibly metallic. I had a hunch what it was, and an X ray confirmed that hunch. The material showed up on the negative X-ray films as pure white. That’s because it was radiographically opaque: it was lead spatter, from a bullet. Our victim, 97-23, had been shot in the head before her body was burned.

But could we prove that 97-23 was who we thought she was—Matt Rogers’s missing wife, Patty? In the absence of facial features or teeth, the only way to make a positive identification would be a DNA test. DNA testing had become widely available about five years before, in the wake of the Gulf War of 1990 to 1991. In this case, though, genetic testing might or might not work: DNA is destroyed by intense heat, and these bones had been subjected to heat intense enough to cremate them, in effect. Our only hope was that the cervical vertebrae or the unburned chunk of the right parietal—the piece that had probably broken away when the bullet smashed into the skull—might yield enough DNA to be compared with samples from Patty’s blood relatives. We sent one of the vertebral fragments off to a private forensic laboratory and crossed our fingers as the police requested blood samples from Patty’s parents for comparison.

While we awaited the test results, we resumed our examination of the bones. There remained one more crucial question I hoped we could answer: When had she been killed? Joanne was the ideal assistant to help me answer this question. A year before, she had completed her master’s degree in anthropology. Her thesis project studied how bone is altered by fire.

Joanne’s research looked at bones burned in two kinds of settings. First, she re-created an archaeological setting: she buried prehistoric bones, then built campfires on the ground above them, in order to determine what kinds of changes might have occurred in ancient bones long after they’d been buried—changes that modern archaeologists would need to know how to spot and interpret when excavating ancient sites.

Her second experiment, which was directly relevant to the Rogers case, re-created a realistic forensic setting: Joanne put bones in the crawl space beneath a house, then burned the house to the ground. (Lest anyone think my students are arsonists, let me rephrase that: The house, which had been condemned as unsafe, was burned not by Joanne, but by the fire department, which was kind enough to let Joanne harness the blaze for her research. The fire department’s cooperation might have had something to do with the fact that Joanne was dating a firefighter, who is now her husband.)

For her research specimens Joanne used deer bones, which are abundant in Tennessee and are very similar to the bones of humans. She laid some bones on the dirt in the crawl space, buried some bones about an inch beneath the surface, and buried others about two inches deep. Then, with help from a liberal sprinkling of gasoline, the house began to burn.

It burned fast. In just two and a half hours, the wooden house was reduced to smoldering embers. Joanne let it cool overnight, then went back the next day to retrieve her bones and her thermal probes, which measured the peak temperatures to which the bones were exposed. In the crawl space itself, temperatures shot up to about 1,700 degrees Fahrenheit; one inch under the ground, the temperature reached about 1,260 degrees Fahrenheit; and two inches down, it got up to a toasty 1,080 degrees Fahrenheit. The severe heat created numerous cracks in the bones, especially the bones on the surface. Those specimens were riddled with fractures, both longitudinal (lengthwise) and transverse (crosswise, or circumferential).

Joanne’s bone specimens for her thesis research were defleshed and dry, but after she got her degree, she conducted