“Hmmm,” he said. “So you didn’t notch the end you cut.” He glanced at me.

He wasn’t chastising, just reminding, and I felt angry with myself again. Usually, I was so careful. If anything, I was known for being cautious to the point of obsession.

“I made an assumption, and I was wrong,” I said. “I did not expect to discover that the killer used a saw with characteristics very similar to mine.”

“They usually don’t use autopsy saws.” He pushed back his chair and got up. “I’ve never had a case, really, just studied that type of saw mark in theory, here in the lab.”

“Then that’s what this is.” I had suspected as much.

“I can’t say with certainty until I get it under the scope. But both ends look like they’ve been cut with a Stryker saw.”

He gathered the bags of bones, and I followed him out into the hall as my misgivings got worse. I did not know what we would do if he could not tell the saw marks apart. A mistake like this was enough to ruin a case in court.

“Now, I know you’re probably not going to tell much about the vertebral bone,” I said, for it was trabecular, less dense than other bone and therefore not a good surface for tool marks.

“Never hurts to bring it anyway. We might get lucky,” he said as we entered his lab.

There was not an inch of empty space. Thirty-five-gallon drums of degreaser and polyurethane varnish were parked wherever they would fit. Shelves from floor to ceiling were crammed with packaged bones, and in boxes and on carts were every type of saw known to man. Dismemberments were rare, and I knew of only three obvious motivations for taking a victim apart. Transporting the body was easier. Identification was slowed, if not made impossible. Or simply, the killer was malicious.

Canter pulled a stool close to an operating microscope equipped with a camera. He moved aside a tray of fractured ribs and thyroid cartilage that he must have been working on before I arrived.

“This guy was kicked in the throat, among other things,” he absently said as he pulled on surgical gloves.

“Such a nice world we live in,” I commented.

Canter opened the Ziploc bag containing the segment of right femur. Because he could not fit it on the microscope’s stage without cutting a section that was thin enough to mount, he had me hold the two-inch length of bone against the table’s edge. Then he bent a twenty-five-power fiber optics light close to one of the sawn surfaces.

“Definitely a Stryker saw,” he said as he peered into the lenses. “You got to have a fast-moving, reciprocating motion to create a polish like this. It almost looks like polished stone. See?”

He moved aside and I looked. The bone was slightly beveled, like water frozen in gentle ripples, and it shone. Unlike other power saws, the Stryker had an oscillating blade that did not move very far. It did not cut skin, only the hard surface it was pressed against, like bone or a cast an orthopedist cut from a mending limb.