“Very good. That’s what I’d say.”

“Pre- or postmortem?”

“Oh, pre. Cuts in green bone are different from cuts made in bones after death, when they’re more brittle. This is a clean, smooth cut. Definitely pre-mortem.”

“Cause of death?”

Dr. Cooper frowned. “I can’t say that for certain,” she said. “I mean, there could have been lethal poison in the system, or the victim might have drowned first, but what I can say, in my opinion, is that the wound would have been sufficient to cause death. If you follow the trajectory of the blade to its natural destination, it pierces the heart.”

Michelle paused a moment, looking at the rib in question, to take it all in. “Front or behind?” she asked.

“Does it matter?”

“If it was done from behind,” Michelle explained, “it could have been a stranger. If it happened from the front, someone had to get close enough to the boy to do it without his knowing what was going to happen.”

“Yes, I see,” said Dr. Cooper. “Good point. I never have managed to get the hang of thinking the way you police do.”

“Different training.”

“I suppose so.” Dr. Cooper picked up the rib. “Judging from the position of the cut on the bone—see, it’s almost on the inside—and by the straightness I’d say that it was done from in front, the classic upthrust through the rib cage and into the heart. Harder to be that accurate from behind. Much more awkward, far more likely to be at an angle.”

“So it had to be someone he would let get that close to him without being suspicious.”

“Close enough to pat him on the shoulder, yes. And whoever did it was right-handed.”

“What kind of knife?”

“That I can’t tell you, except that it was very sharp and the blade wasn’t serrated. It’s quite a deep cut, as you can see, so there’s plenty of scope for analysis and measurement. There’s someone I know who can probably tell you the date it was made and the company who made it, an expert. His name’s Dr. Hilary Wendell. If you like I can try to track him down, get him to have a look?”

“Could you?”

Dr. Cooper laughed. “I said I’d try. Hilary’s all over the place. And I mean all over. Including the United States, and Eastern Europe. He’s very well known. He even spent some time with the forensic teams in Bosnia and Kosovo.”

“You were there, too, weren’t you?”

Dr. Cooper gave a little shudder. “Yes. Kosovo.”

“Any idea when the coroner can release the bones for burial?”

“He can release them now as far as I’m concerned. I’d specify burial rather than cremation, though, just in case we need to exhume.”

“I think that’s what they have in mind. And some sort of memorial service. It’s just that I know the Marshalls are anxious for some sense of closure. I’ll give them a ring and say it’s okay to go ahead and make arrangements.”