“So you would think,” I said. “Watch this.” I took a small wire brush to the tread of his shoe, carefully scraping out the nearly invisible gunk from between the ridges of the tread into a petri dish.
I lifted a small sample of it onto a glass slide and took it back over to the microscope. Astor immediately crowded in to look, but Cody hopped over quickly. “My turn,” he said. “My shoe.” She looked at me and I nodded.
“It’s his shoe,” I said. “You can see right after.” She apparently accepted the justice of that, as she stepped back and let Cody climb onto the stool. I looked into the eyepiece to focus it, and saw that the slide was everything I could hope for. “Aha,” I said, and stepped back. “Tell me what you see, young Jedi.”
Cody frowned into the microscope for several minutes, until Astor’s jiggling dance of impatience became so distracting that we both looked at her. “That’s long enough,” she said. “It’s my turn.”
“In a minute,” I said, and I turned back to Cody. “Tell me what you saw.”
He shook his head. “Junk,” he said.
“Okay,” I said. “Now I’ll tell you.” I looked into the eyepiece again and said, “First off, animal hair, probably feline.”
“That means cat,” Astor said.
“Then there’s some soil with a high nitrogen content—probably potting soil, like you’d use for houseplants.” I spoke to him without looking up. “Where did you take the cat? The garage? Where your mom works on her plants?”
“Yes,” he said.
“Uh-huh. I thought so.” I looked back into the microscope.
“Oh—look there. That’s a synthetic fiber, from somebody’s carpet.
It’s blue.” I looked at Cody and raised an eyebrow. “What color is the carpet in your room, Cody?”
His eyes were wide-open round as he said, “Blue.”
“Yup. If I wanted to get fancy I’d compare this to a piece I took from your room. Then you would be cooked. I could prove that it was you with the cat.” I looked back into the eyepiece again. “My goodness, somebody had pizza recently—oh, and there’s a small chunk of popcorn, too. Remember the movie last week?”
DEXTER IN THE DARK
241
“Dexter, I wanna see,” Astor whined. “It’s my turn.”
“All right,” I said, and I set her on a stool next to Cody’s so she could peer into the microscope.
“I don’t see popcorn,” she said immediately.
“That round, brownish thing up in the corner,” I said. She was quiet fo
r a minute, and then looked up at me.
“You can’t really tell all that,” she said. “Not just looking in the microscope.”
I am happy to admit that I was showing off, but after all, that’s what this whole episode was about, so I was prepared. I grabbed a three-ring notebook I had prepared and laid it open on the counter.
“I can, too,” I said. “And a whole lot more. Look.” I turned to a page that had photos of several different animal hairs, carefully selected to show the greatest variety. “Here’s the cat hair,” I said. “Completely different from goat, see?” I flipped the page. “And carpet fibers. Nothing like these from a shirt and this one from a wash-cloth.”
The two of them crowded together and stared at the book, flipping through the ten or so pages I had put together to show them that, yes indeed, I really can tell all that. It was carefully arranged to make forensics look just a tiny bit more all-seeing and all-powerful than the Wizard of Oz, of course. And to be fair, we really can do most of what I showed them. It never actually seems to do much good in catching any bad guys, but why should I tell them that and spoil a magical afternoon?
“Look back in the microscope,” I told them after a few minutes.
“See what else you can find.” They did so, very eagerly, and seemed quite happy at it for a while.
When they finally looked up at me I gave them a cheerful smile and said, “All this from a clean shoe.” I closed the book and watched the two of them think about this. “And that’s just using the microscope,” I said, nodding around the room at the many gleaming machines. “Think what we can figure out if we use all the fancy stuff.”
“Yeah, but we could go barefoot,” Astor said.