“Shit,” Neilsen breathes.

“What is it?” Emma’s pulse quickens.

“Could it have been the way they were tied?” Cooper asks quickly.

Westfall answers first. “Nope. Otherwise you’d see angle variation in the bruising. And we got impressions off the posterior torsos—it looks as if all the knots were at the back. So the rope marks should be evenly distributed.”

“Shit,” Neilsen says again, more loudly this time. “He’s right. Here’s the shots for Lambton and Davis—same thing. Left cubital fossa is more damaged. Goddammit.”

“Hey, man, don’t feel bad,” Dixon consoles.

Emma frowns. “What does this mean?”

“It means our perp created deeper abrasions,” Dixon explains, “knowing that the debridement would disguise something in the elbow joint. Probably a needle mark, like you suggested. That much abrasion, it all bleeds together. It’s the old ‘forest for the trees’ strategy.”

“Would he have done it postmortem?” Cooper asks.

“Doesn’t matter. Before death, just after—it’d be hard to differentiate either way. He might’ve used a file or a rasp, or the same rope, maybe, so the abrasions would match with the ligature marks.”

“I’ll be damned,” Westfall says. He looks at Emma. “We’ll need to get the county MEs to dissect and confirm, but it seems like your theory might have legs, Miss Lewis.”

“So he is drawing blood.” Emma gets a rush of energy, but it fades when she considers the ramifications. “But why is he drawing blood, then, if it’s not to determine blood type?”

“Didn’t you say he could be drinking it?” Bell asks.

“That may not fit, I’m afraid,” Neilsen says. “Blood is toxic if you ingest more than a teaspoon or two. It can make you vomit, produce hemochromatosis.”

“Iron overload,” Westfall supplies.

“Maybe he’s only ingesting a little bit?” Emma suggests. “Gutmunsson compared it to a taste test.”

“You got this lead from Simon Gutmunsson? ¡Ay Santo!” Dixon raises and lowers his monobrow. “I guess blood-drinking is possible. But the Pennsylvania perp doesn’t have the disorganization you’d expect to see with that kind of paraphilia. Guys like Richard Chase, who think they’re vampires, tend to demonstrate heavy-duty schizophrenia—they’re completely chaotic.”

“Do the victims all have the same blood type?”

“Nope. Lambton and Ramirez were O-positive, Barnes was A-neg, and Davis was B-positive.”

Bell is looking at the photos under the harsh lamplight. “Could he be… I dunno, injecting it into himself? Something like that?”

“Like a transfusion?” Dixon asks.

He sees something glowing in them, something he wants to kindle inside himself.… Emma wants to shake off Simon Gutmunsson’s voice in this office, but it seems to follow her everywhere. “That would actually mesh very well with what we understand of the killer. We know he doesn’t kill the victims immediately—Gutmunsson suggested he waits for the blood to be largely clear of ether, to be rid of impurities. The killer seems to have a special relationship with the blood from the victims. I can see him wanting to make their blood a part of him somehow.”