Carved in Bone

knife wound, one whose trajectory I had been unable to replicate in a corpse.
    As Tammy Wynette belted out the final chorus, the backhoe rumbled into the cemetery and followed a deputy’s hand signals to Ledbetter’s grave. At a nod from Bob Roper, the machine began clawing at the rocky red soil.
    The soil was still soft—it takes years for disturbed earth to re-compact, and even then, it’s never as hard as it was before being disturbed. Anthropologists depend heavily on that property; it’s what allows us to find and excavate ancient burials. Early in my career, for instance, I had spent more than a dozen summers excavating centuries-old graves of Arikira Indians in South Dakota, staying just one step ahead of the rising waters of a new Corps of Engineers reservoir. The Arikira graves—circular in shape—lay beneath a foot of fine, windblown topsoil. After a couple of summers of backbreaking manual searching, I did some experimenting and found that a road grader was the perfect tool for exposing the tops of the graves: a series of shallow passes with the grader would gradually remove the foot of topsoil in long, even rows; as soon as it reached the level of the graves, neat circles of fluffier, disturbed earth would appear. The power equipment increased our speed by a factor of ten—delighting our Smithsonian sponsors at the time, and dismaying Indian activists years later.
    Crime scene technicians rely on this property of the soil, too. Rather than digging up an entire field or forest where a body is thought to be buried, the technician jabs the ground with a T-shaped probe—a thin steel rod with a handle welded across one end. If the probe resists going in, the soil is probably undisturbed, but if it plunges in easily, the technician knows somebody’s been digging there recently. An even higher-tech version of the soil probe is ground-penetrating radar, which we’ve helped refine at the Body Farm: just by dragging a scanner across the surface of the ground, a skilled technician can tell (by reading magnetic sworls and squiggles that look utterly random to me) the relative density of the soil and can spot areas of disturbance.
    The backhoe clattered and bucked as it clawed open the grave. Scoop by scoop, the pile of dirt beside the grave grew steadily. Finally a sharp clatter and scraping sound told us that the operator had reached the top of the concrete vault that surrounded the coffin itself. After a few more scrapes—which set my teeth on edge like a hundred sets of fingernails raking down a hundred blackboards—he raised the scoop and clambered down off the tractor. Retrieving a pair of steel chains from the back of the rig, he snagged four metal hooks into eyebolts on the lid of the vault and tied the chain over the bucket of the backhoe. Once back in the driver’s seat, he took up the slack in the chain and hoisted the concrete lid. As it rose from the grave, red clay crumbled off the edges of the concrete. Swinging it to one side, the operator set it on the damp grass, crushing a stray and faded plastic bouquet.
    “Doc, how come graves are lined with those big concrete things, anyway?” DeVriess asked. “Seems kinda pointless. I mean, the body’s going to decay anyway, right?”
    “Sure,” I said. “But people—the living, the ones that funerals and coffins and cemeteries are meant to console—don’t like to think about that, so they try to postpone it with embalming fluid and stainless-steel coffins and reinforced concrete vaults.” DeVriess rolled his eyes and shook his head at the folly. I didn’t like that—didn’t like his smug, superior attitude—so I went on. “You think it’s dumb?” He gave a noncommittal sideways nod. “For the sake of your client, you better hope this vault stayed nice and tight, and that flimsy wooden coffin stayed dry, and the undertaker didn’t scrimp on the embalming fluid the way so many of them do. Those might be the only things that can save his neck and save your case.” My voice had risen as I spoke, and I noticed several people looking at us. I snapped my mouth shut and moved to the other side of the grave.
    The vault had kept out most of the groundwater, but not all. The rubber gasket that ran around the top of the vault’s walls must have slipped slightly out of position, for a small loop of it dangled muddily into the vault, showing where the seal had failed. A greasy moat several inches deep surrounded the coffin, which bobbed