“I like to take notes.”

“You’re trying to quit smoking,” she said matter-of-factly. “It gives you something to do with your hands.”

“You missed your calling as a detective.”

“Your teeth—smoker’s stain. Probably also coffee stain,” she said, staring at his mouth. “Sorry. It’s an occupational hazard. Make an appointment with Kelly and I’ll do a really nice polish job, gratis.”

“I’ll do that just as soon as I find a spare minute.”

“I’ve heard that excuse before.” She smiled impishly and covered the screen with a four-by-ten radiograph.

“This X ray is a panoramic view of Doe One’s mouth. It covers all the bony structures of the mandible and maxilla from ear to ear, thereby giving us a good overall look at jawbones and teeth. It’s not great for detail, but you can see her third molars hadn’t erupted. Here they are, just tooth buds in her jaw.”

She pointed to four spots on the radiograph. Inside the jawbone next to well-defined teeth were small white disks that looked like cotton balls delineated by a white circle.

“What’s the circle?” he asked.

“The lining of the tooth follicle. Normal radiographic feature. You can see her third molars—the wisdom teeth—much more clearly on these radiographs.” She placed several small X rays on the screen. “These are called ‘periapicals’ and these are called ‘bite-wings’—the kind of X rays you normally have taken by the dentist. They give much better detail than the ortho-pantogram. Judging from the maturation of her molars, I’d put Jane Doe One at about fifteen or sixteen.”

She placed another celluloid on the screen. “This is the panoramic of Doe Two. Her third molars hadn’t erupted either, but that’s because they were impacted. Eventually, they would have had to be extracted. But you can see for yourself how much more differentiation there is in the tooth crown; root development had already taken place. This girl was around twenty, twenty-one at the time of her death.”

She clicked off the light and looked at Decker.

“I’ll tell you something else about the two girls, Pete. They may have died on the pyre together, but they didn’t come from the same neighborhood.”

“Why do you say that?”

Hennon walked over to the Formica table and picked up several pink plaster casts of teeth and gums.

“This is a cast of Jane Doe One’s teeth. Let’s call her Jean. Jean has had orthodonture; her teeth are beautifully aligned, although I betcha she hadn’t been wearing her retainer as much as she should have. We’ve got a little lippage here. But be that as it may, her occlusion is A-1 and she’s had serial extraction.”

“What’s that?”