the cracked bones, for sure, but we wouldn't see the ligament stretching at all."
"What about a knee?"
"A knee in the ribs? That's similar to a punch. Blunt, but an essentially circular impact site. The ligament stretching would show a completely different pattern."
Walker drummed his fingers on his desk. He was starting to sweat. "Any way a person could have done it?" he asked.
Black shrugged. "If he were some kind of contortionist, maybe. If he could hold his whole leg completely rigid and somehow jump up and hit her in the side with it. Like it was a fence railing. I would say it was completely impossible."
Walker went quiet for a second. "What about the bruised shin?" he asked.
Black swapped the third file into his hand. Opened it and read through the description of the contusion again. Then he shook his head.
"The shape of the bruise is crucial," he said. "Again, it's what you'd get from the impact of a long hard rounded object. Like a fence rail again, or maybe a sewer pipe, striking against the front of the shin at an oblique angle."
"Could he have hit her with a length of pipe?"
Black shrugged again.
"Theoretically, I suppose," he said. "If he was standing almost behind her, and somehow could reach over her, and he swung a hard downward blow, and struck her almost but not quite parallel with her leg. He'd have to do it two-handed, because nobody can hold a six-inch diameter pipe one-handed. Probably he'd have to stand on a chair, and position her very carefully in front of it. It's not very likely, is it?"
"But is it possible?"
"No," Black said. "It isn't possible. I say that now, and I'd certainly have to say it under oath."
Walker was quiet again.
"What about the collarbone?" he asked.
Black picked up the last report.
"These are very detailed notes," he said. "Clearly an excellent physician."
"But what do they tell you?"
"It's a classic injury," Black said. "The collarbone is like a circuit breaker. A person falls, and they try to break their fall by throwing out their hand. Their whole body weight is turned into a severe physical impact which travels upward as a shock wave through their rigid arm, through their rigid shoulder joint, and onward. Now, if it wasn't for the collarbone, that force would travel into the neck, and probably break it, causing paralysis. Or into the brain pan, causing unconsciousness, maybe a chronic comatose state. But evolution is smart, and it chooses the least of all the evils. The collarbone snaps, thereby dissipating the force. Inconvenient and painful, to be sure, but not life-threatening. A mechanical circuit breaker, and generations of bicyclists and inline skaters and horseback riders have very good reason to be grateful for it."
"Falling can't be the only way," Walker said.
"It's the main way," Black said. "And almost always the only way. But occasionally I've seen it happen other ways, too. A downward blow with a baseball bat aimed at the head might miss and break the collarbone. Falling beams in a burning building might impact against the top of the shoulder. I've seen that with firefighters."
"Carmen Greer wasn't a firefighter," Walker said. "And there's no evidence a baseball bat was involved any other time."
Nobody spoke. The roar of the air conditioners filled the silence.
"O.K.," Walker said. "Let me put it this way. I need evidence that there was violent physical abuse against this woman. Is there any here?"
Black went quiet for a spell. Then he simply shook his head.
"No," he said. "Not within the bounds of reasonable likelihood."
"None at all? Not even a shred?"
"No, I'm afraid not."
"Stretching the bounds of reasonable likelihood?"
"There's nothing there."
"Stretching the bounds all the way until they break?"
"Still nothing. She had a normal pregnancy and she was an unlucky horseback rider. That's all I see here."
"No reasonable doubt?" Walker said. "That's all I need. Just a shred will do."
"It's not there."
Walker paused a beat. "Doctor, please let me say this with the greatest possible respect, O.K.? From a DA's point of view, you've been a pain in the rear end many more times than I can remember, to me and my colleagues throughout the state. There have been times when we're not sure what you've been smoking. You've always been capable of coming up with the most bizarre explanations for almost anything. So I'm asking you. Please. Is there any way at all you could interpret this stuff differently?"