“Her friends say she had an early drink before dinner,” Ellie cut in, “but then the real partying started around ten. She was definitely still drinking at ten thirty, and the club closed at four.”

Karr nodded, looking up to the ceiling as he ran the numbers. “Very well, then. Assuming she continued her consumption, I’m probably correct that she was still on the upswing at the time of death. With a body weight of only a hundred and twenty-two pounds, my best guess is she must have consumed nine or ten drinks over the course of the night.”

Ellie shook her head at the stupidity of it all. Attractive girl, scantily clad, underage. Blasted out of her mind. Wandering the streets of Manhattan alone in the middle of the night. A few times a year, a handful of girls were killed after making the identical mistake. And no one seemed to learn.

“Plus we’ve got the tox screen. Positive for crystal meth.”

That one caught Ellie by surprise. She liked to think she could spot a liar, and none of the usual red flags went up with Chelsea’s friends. They’d been clear: no sex, no drugs.

“Can you tell how recent?”

“She used within four hours of her death.”

Add methed up to attractive, scantily clad, underage, and drunk. Ellie couldn’t think of a more dangerous combination.

Rogan cut in with a question of his own. “CSU thought the vic was killed off-site and then moved to the East River scene.”

“Oh, yes. Certainly. As you might know, it’s the power of the beating heart that keeps our blood cells and platelets all mixed together in our vessels.” He pantomimed a mixing gesture with his hands. “So once the heart stops beating, and the mixer loses its power, the red blood cells begin to settle with gravity. That’s what causes the telltale discoloration of lividity-that look of a layer of grape jelly beneath the skin.”

“And the discoloration on Chelsea?” Ellie asked.

“Her body may have been found propped up in a seated position, but the grape jelly was on her back.”

It meant that Chelsea Hart’s body was lying faceup after her death and was then moved into the position in which she was found.

“The movement of the body was not the only postmortem activity. Based on the minimal amount of blood on the wounds’ edges, my best estimation is that the cuts you saw on her arms, legs, and face were inflicted after death. If you told me she’d been immersed in water-a hot tub or a bath, for example-I might revise my opinion to antemortem cuts, but there’s no evidence of that, especially in light of the speed with which the body was discovered.”

“So cause of death is strangulation?”

“I still need to complete the entire autopsy, but yes, I’m confident that’s what I will ultimately conclude. Looking at the pattern of bruising on her neck, you can see she was strangled manually, from the front.” He held his hands out, fingers strong and splayed. “Thumbs at the larynx, palms on the carotid arteries, fingers wrapped all the way around the back of her neck. With her on her back, and him on top of her, it creates a tremendous amount of pressure.”

Manual strangulation was in many ways the most dedicated form of murder. It wasn’t an instantaneous decision, like the pulling of a trigger or the slashing of a throat. It wasn’t remote, like poison or a contracted kill.

And there was nothing to physically separate the killer from his victim-no rope, no scarf, no belt to do the strangler’s job for him. Everything about the act guaranteed that if the killer had any kernel of doubt-any second of hesitation-he could stop. Among murderers, stranglers who used their bare hands were the most committed and least repentant.

And they were almost always motivated by sexual desire.

“Any evidence of sexual assault?” she asked.

“Surprisingly, there was no indication of either vaginal or anal trauma. I did a rape kit anyway, obviously. Sometimes we get a hit on the oral swab. It will take a couple of days for the initial results on the swabs-weeks for any DNA profile, if we do in fact have any fluids to examine. Will there be evidence of voluntary sex within the last few days?”

“Not according to her friends. She has a boyfriend who’s supposedly been in Mexico all week.”

“Well, at least we’ll know that any DNA we find is for us. That’s all I have for you now,” Karr said, switching gears abruptly, “but I’ll be in touch when we get those labs back.”

As they walked back to the car in the sunshine that was warming the cold morning into day, Ellie thought about the last hour of Chelsea Hart’s life and the fear and pain she must have experienced. Then she pictured Chelsea two hours earlier, smiling, dancing, and telling her best friend that she was having the best night ever.

CHELSEA HART’S FAVORITE MOVIES were Run Lola Run, The Notebook, and The Princess Bride. Her favorite books were Wuthering Heights and The Unbearable Lightness of Being. Her favorite drink was called an Angel’s Tip, a mix of dark crème de cacao and heavy cream that she swore prevented hangovers. She wanted to meet Ellen DeGeneres and Johnny Depp.

She had ninety-two friends.

Ellie scrolled through Chelsea’s MySpace profile one more time as she snacked on spoonfuls of the Nutella spread she kept in her top desk drawer.

“You sure you don’t want any?” she asked, extending the open glass jar in Rogan’s direction.

He glared at her. “Are we going to continue this ritual every afternoon? You offer me that funky stuff you call food, so I can say, No, thank you?”

She pulled the jar back and removed a healthy spoonful. “Seems rude not to offer.”

“You can offer it to me today, tomorrow, and every day ’til I retire, and I promise I will always decline. So consider yourself excused from all social obligation when it comes to that stuff.”

That was fine with Ellie. No sharing meant more for her.

Chelsea Hart’s top MySpace friends were Stefanie, Jordan, and a Mark whom Ellie assumed was her boyfriend, Mark Linton. She listed as her heroes “my parents, friends, and random-ass people I meet everyday.”

Ellie clicked on the link that read “My Pictures.” The majority of the photographs depicted groups of teenagers clustered together, arms around each other’s shoulders, smiling for the camera. Chelsea was in the middle of most of the clusters. Stefanie was almost always close by.

An entire photo album was devoted to a white-and-brown English bulldog that was apparently named Stacy Keach. Another contained pictures of Chelsea in various high school theater productions-God-spell, A Chorus Line, Into the Woods. Another of Chelsea in a purple-and-gold track uniform. Ellie stared at the intensity in Chelsea’s face-a perfect blend of happiness, pride, and pain-as she pressed through the ribbon across a finishing line, and she wondered how a girl like this had wound up drunk, alone, and on crystal meth in New York City.

“We need to get hold of Chelsea’s parents,” Ellie said. “All I did was Google the name Chelsea Hart, and her MySpace page popped right up. Once the news hits, every member of the press will be scouring this for all the details about Chelsea’s personal life. They need to pull it down.”

“They’ve got to be on a plane by now. When I talked to them this morning, they sounded like they were literally going straight to the airport once we hung up.”

“Knock, knock.” Jack Chen rapped his knuckles against an imaginary door. “Detectives, there’s a couple here to see you. They say they’re Chelsea Hart’s parents?”

“Talk about on cue.” Ellie gave a mock shudder. “Creepy.”

Rogan’s phone rang. He held up an index finger toward her before answering. “Rogan… Correct. That’s my case… Yes, I believe they just walked into the precinct a second ago… That goes without saying… Of course… I’ll be sure to tell them you called.”