“The voids?” she whispered now, pointing to twin patterns of clean white sheet amid the large cylinder of blood.

Alex got out a pencil. With his left hand, he started pointing and explaining. “Remember, the postmortem mutilation is mostly to the torso and the upper thighs. If you look at the bloodstain, you can see feathering at the top, and imprints here, which I believe are from the victim’s shoulder blades pressing into the sheet and limiting the absorption of blood. Orienting ourselves, then, here is the head, the shoulders, the torso, the legs. Given that . . .”

“The voids are on either side of the victim’s thighs.”

“From the lower part of the killer’s legs, I presume. Essentially, he was straddling her body, the front part of his shins pressing against the mattress on either side of her thighs, which shielded that part of the sheet from blood.”

“He incapacitates his victim,” D.D. murmured, trying to form a sequence of events in her mind. “Then, most likely, he sets the scene. The champagne, handcuffs, single rose. He’d want to get everything out before things get too . . . messy.”

Alex turned, sweeping his high-intensity beam across the nightstand where the champagne bottle and other props awaited. The light didn’t expose a single drop of blood.

“Fair assumption,” he said.

“Next . . . he would have to strip the victim. Expose her skin.”

Light beam to the left-hand side of the bed, where D.D. now saw a puddle of dark clothes.

“Black sweats, oversize Red Sox T-shirt, underwear,” Alex reported.

“Sounds like suitable PJs for a single woman. He cast them aside.”

Another nod.

“Then”—she turned toward the bed—“he climbs aboard, positions himself astride the victim’s naked body, and begins to . . . skin her. Why?”

Alex shrugged. “Part of the ritual? Maybe the killer is really some kind of necrophiliac, and it’s these moments with the body that are most fulfilling for him. The strips of skin are thin, and based on the ME’s study of the first victim, they’re precise, methodical. In his estimation, the killer spent at least an hour on the filleting process, if not two or three.”

“Semen?” D.D. asked. “Signs of sexual assault?”

“First victim, no. Second victim, results still pending.”

“I don’t get it. He gains access, incapacitates his victims. Drugs them?”

“Tox screen also pending.”

“Then . . . starts in with the knife. For at least an hour?”

“With some skill,” Alex provided. “ME suggests either a hunter or maybe even a butcher. But based on the smooth, even strokes, our killer has some experience.”

“Kind of blade?”