July 4, 2012, was a scorcher in Star City, West Virginia—a prelude to what would become the hottest month that year. While some escaped the heat by watching The Amazing Spider-Man or Magic Mike in the cool dark at the nearby Morgantown Mall or swimming in the Monongahela River, 16-year-old Skylar Neese was moping around her family's apartment, beyond bored. Feeling ditched by her friends who'd gone away together, she tweeted her frustration: sick of being at fucking home. thanks "friends", love hanging out with you all too.

"I said, 'Skylar, why don't you read a book?' " recalls her mother, Mary, sitting in the family room, gesturing toward the full bookcase. "She devoured the Twilight books. She was just getting into the classics. She loved Great Expectations."

With bright blue eyes (a gift from her mother), ivory skin, and a dimpled chin, Skylar was an honors student at University High School heading into her junior year, excelling in two subjects she couldn't stand: math and science. By July she'd already gotten a jump on the required summer reading: Susan Sontag's Regarding the Pain of Others and Saul Bellow's 1959 surrealist novel Henderson the Rain King, in which the protagonist speaks in pitch-perfect Twitter verse: "If I don't get carried away I never accomplish anything…Alone I can be pretty good, but let me go among people and there's the devil to pay." And every teenager's cri de coeur: "I want, I want, I want, I want, I want!" Skylar wanted to be out with her best friends. Before going to sleep that night she tweeted: stress will be the death of me.

The next day, Thursday, after working the evening shift at Wendy's, she went home, where her parents were watching television—Mary sitting in an overstuffed recliner and her father, Dave, lying on the couch. She kissed them both, and told them she loved them and that she was tired and going to bed.

The next time, the last time, they saw their only child was in a grainy black-and-white video. She was sneaking out her ground-floor bedroom window in the middle of the night, her purse over her shoulder, hair swinging as she hurried across the small parking lot to a waiting car. Watching Skylar climb into the backseat during those last few seconds of footage retrieved from the apartment building's security camera, there's an urge to call out to her, No! Don't go! But the door closes, the car pulls away, and she's gone.

If you were ever a 16-year-old girl, you have a war story. Even the luckiest, prettiest, most gifted, most popular girl has a scar somewhere. We've all taken aim. We've all been targeted. We are all every character in Lord of the Flies and Mean Girls, or any one of those trying to survive in The Hunger Games.

In an adolescent's game of thrones, one needs an ally, someone to fend off the slings and arrows of rivals and bullies. Skylar and Shelia Eddy had been close as kin since they were seven or eight years old. "Shelia didn't even knock on the door when she came over, she just came on in," recalls Dave Neese, a large, muscular, softhearted man with dark eyes and a butch haircut. Always bringing home strays, Skylar immediately took to Shelia, an only child of divorced parents. A slip of a thing, 100 pounds soaking wet, Shelia was as wild as the Appalachian Mountains around them. "Skylar thought she could save her," says Mary, an administrative assistant. "I would hear her on the phone givin' Shelia all kinds of hell: Don't be stupid!What were you thinkin'? On the other hand, Shelia was so much fun. She was always silly and doin' crazy stuff."

Their freshman year at UHS—the first school they attended together—Skylar and Shelia met Rachel Shoaf, a Catholic middle-school grad who had an older half brother. Where Shelia ran unsupervised, Rachel, also a child of divorced parents, came from a strictly religious home. That fall, the girls became a trio of best friends, with Skylar and Rachel each angling to be the one closer to Shelia, who reveled in her sway.

It's no accident that Girls and Sex and the City revolve around four friends instead of three. Three's a crowd, and four, or five, or more, against all mathematical reason, isn't. Any girl who's been caught in a social triangle knows this. She knows too the undercurrent of anxiety felt by all, recognizing that the degrees of love and the balance of power are always shifting. The problem, wrote the late Thomas Fogarty, MD, a respected family-systems psychiatrist and an expert on relationship triangles, "is that the lines (relationships) are fixed, closed, determinative of each other." Any action in one position forces a reaction in the others, so that "they find closeness difficult to maintain and…one person overlaps the other so that there is an indistinctness…It is difficult to tell what is self and what is the other person," leaving the third person at a distance—still inside, but at a remove, observing the closeness she longs to experience, and feeling abandoned.

Attractive in distinct ways, the teens were straight out of a CW Network casting call: Rachel was redheaded, tall, religious, a star in the school plays. Skylar, the brunette, was cherubic, spirited, loyal. And Shelia, sometimes bottle blond, sometimes raven haired, was game for anything, charismatic, sexual, the kind of beauty you'd see waving atop a float in a small-town parade. While they lived in different suburbs of Morgantown, they were living together virtually in the digital realm. They spent their waking lives posting, texting, tweeting, retweeting—having whole conversations in 140 characters, emoting in emoticons. As Skylar tweeted on April 4, 2012: twitter seems to like, swallow me, at times.

this image is not available
Hellin Kay

You get the same feeling crawling through the tweet tunnels of the threesome. Their tiny missives, more than 9,400 posts, quickly telegraph who the girls are and what they want, want, want, want, want: what they're thinking and feeling, or unable to feel. They're like the dots in a Georges Seurat painting—seen together, a picture emerges, although, context being everything, it's only fair to draw from tweets that are statements—not conversations or reactions, just declarations. First, Skylar's: mosquitoes are disgusting creatures from hell…everything about my parents driving pisses me off…it amazes me how the moon seems like it jumps across the sky when you drive like 2 feet. …@_racchh's singing is breath taking <3… I like Obama… s/o to my dad for getting me mcdonalds!!… life would be so much easier if jealousy didn't exist. … I stop listening as soon as my teacher says it wont be on the test. …omg saved by the bell is on… wrapping presents for @_sheliiaa's family even though i never do for my own. …Life without sweet tea would SUCK.… I love my dog more than anything in the world… apparently my purse is a black hole…every dude at walmart right now smells like a god….

Rachel's Twitter account ceased to exist as of May 2013, but her tweets were still on Topsy, a Twitter index, until last February, when they were scrubbed from there, too. Her self-portrait looks like this: i want to go to hogwarts more than anything…chinese food is my fave… a day with me and shelia is never a dull day lol…all i want right now is cheesecake…Don't make a permanent decision for a temporary emotion…sometimes i wish i didn't fall in love… giving up crying for lent…tangled is such a good movie then he cuts her hair off and im like ew wtf no… snow makes everything more quiet… if I was a lesbian hannah hart would be my girl… i have the most realistic nightmares …beyonce is so sexy, damn…breakfast club is my all time favorite movie… if it aint your parents its the damn police…am i the only one that thinks the girl from the girl with the dragon tattoo is beautiful?… ohhh how i missed you sandals <3…yesss the bible is on… i can't remember what's a dream and what's reality anymore…

The lion's share of the tweets—4,374—came from Shelia, who, without a steady job or the demands of rehearsing a play, had time on her hands—enough time to write almost as many as Rachel and Skylar combined: i wish it was acceptable to be naked all the time… kardashian marathon, love my life…it's okay if you hate me as long as i hated you first… i miss my bestfwend … love having the upper hand…stepdad, stop walking around the house without a shirt, it's gross. not to mention your boobs are bigger than mine. …i wonder what it's like to be good at math… shit i love my hair long, im never gonna cut it…there's a reason why "sober" and "so bored" sound almost exactly the same… lol my mom underestimates me like its her job…megan fox is the definition of perfection lezbihonest…you're fat because i hate you…i cannot express how much i love being naked… ah law and order svu will always bring joy to my life… this generation is fucked. imagine what it'll be like when our kids have kids…don't ignore me when im ignoring you… if you talk about how youre madly in love with justin bieber I probably want to stab you… i look forward to tanning bed naps…when will the kardashians finally adopt me?… you fuel my determination to not have feelings…

Their selfies together capture the girls exuberantly bonded—making faces, striking model poses, being physically affectionate. But by the spring of 2012, Skylar seemed to be feeling the squeeze of displacement, tweeting: too bad my friends are having lives without me. And then: a girl, a girl. a bitch, a bitch.

"Shelia and Skylar were fighting a lot," says Daniel Hovatter, a UHS classmate. "One time sophomore year, me and Rachel were at practice for Pride and Prejudice and Rachel had her phone up to her ear and she was laughing. She was like, 'Listen to this.' Shelia and Skylar were fighting, but Skylar didn't know Shelia had put her on three-way calling and Rachel was listening in."

On May 31, 2012, Skylar tweeted: youre a twofaced bitch and obviously fucking stupid if you thought I wouldnt find out.

And on June 9, a retweet: won't miss anyone from school over summer cause if we're really friends, we'll hangout. If we aren't we won't. Later she tweeted what sounds like a warning: just know I know.

The next day: hope you dont expect me to give a fuck anymore #bye.

Before Twitter, texting, and Instagram, Flickr and Tumblr, the weapon of war was a slam book—a spiral notebook with some miserable kid's name written on the cover, passed among frenemies who filled page after page with nasty remarks and devastating criticism. Eventually the book was tossed or lost, and the kid could recover. But with social media, there's no respite, no half-life for rumors and innuendo. On a whim, you can take your target out with the press of a button and sleep soundly. "There is 100 percent a lack of empathy on the Internet. You don't have to deal with the natural consequences of your behavior," says Jamie Howard, PhD, a clinical psychologist at New York's Child Mind Institute. "You say things you wouldn't say, and your conduct is harsher." Empathy develops when we receive cues from in-person interaction—you say something mean to someone, you see her cry, you feel bad. Technology can obstruct empathy's development and foster detachment.

Teenagers, ruled by a salmagundi of hormones, sex, still-developing prefrontal cortices, and the Internet, which has an ethic of its own, can be particularly brutal. This past June, when two 12-year-old girls in Wisconsin allegedly stabbed their friend 19 times to impress Slenderman, a creepy Internet meme popular in adolescent artwork and video games, one of them told the investigators, "It was weird that I didn't feel remorse."

Not that every kid with a computer and a grudge is at risk for nihilistic violence. "It's a complex mix of bio, psycho, and social," says retired FBI profiler Jim Clemente, a former supervisory special agent in the FBI's Behavioral Analysis Unit in Quantico, Virginia, who helped crack the DC sniper case. "I describe it as this: When somebody kills, genetics loads the gun, personality and psychology aim it, and what you've experienced pulls the trigger. In other words, you're born with your genetics; there's a potentiality there. You could be this good or that bad. There's a range to where you will be. Your personality and your psychology—you actually participate in forming that. The billions of little tiny decisions you make in the privacy of your own mind. And if you have no empathy, it's a lot easier to make decisions that absolutely take nobody else into account. It's all about yourself and narcissism."

When the school year commenced on August 17, 2012, Skylar's missing-person posters were up all over town: "5'4" or 5'5" tall, weighing approximately 135 to 145 pounds…wearing yellow shorts and a multicolored shirt…last seen getting into an unknown car at 12:31 A.M.…"

All anyone knew was what Shelia and Rachel had told the police: that Skylar had sneaked out to meet them at around 11 P.M. to go for a joyride and smoke some pot before Rachel went off to church camp that weekend. (Neither Shelia nor Rachel was willing to speak to me for this story.) Before midnight, the girls said, Skylar had insisted they drop her off at the end of her street, so her parents wouldn't hear the car and wake up. As for the vehicle in the grainy videotape? Whomever it belonged to, whomever she sneaked back out again to meet at 12:31, was anybody's guess. Her last two tweets, posted before she left work at Wendy's on the night of July 5, only added to the speculation: you doing shit like that is why I will NEVER completely trust you. After which she retweeted: All I do is hope.

There's no way of knowing whether Skylar's last tweets were directed at Shelia or Rachel. What is known is that Shelia's Twitter account on July 4 and 5 mysteriously went dormant. Whatever happened on those lost days, Shelia was back at it on July 6 at 6:09 A.M. with a retweet: Always Keep Your Cool.

Rumors fed and spread through social media began flooding the UHS hallways: Skylar had met up with an Internet predator, she'd been involved with the bank robberies in rural Blacksville, she'd OD'd on drugs, she'd run away….

Dave and Mary Neese knew their daughter hadn't run away. "Her contact lenses were still in her bedroom," Mary says. "And her hair straightener—she hated her curly hair—she wouldn't leave home without that. Goody [her mother's old silk nightgown that was Skylar's security blanket] was there. Everything that a girl would take, it was there—toothbrush, hairbrush. She took her cell phone, but not her charger." On August 22, Shelia posted on Facebook this message: skylar come back :( i seriously can't deal with school without you…i miss you too much!

To which Dave replied: she WILL be home soon honey love you.

Shelia: love you too!

"There were rumors that Skylar, Rachel, and Shelia were doing drugs and Skylar overdosed and they were scared so they ditched her body somewhere," Hovatter says. "You had people who wanted to get attention pretending to know what was happening, but no one knew," adds Morgan Lawrence, another UHS classmate and friend of Skylar, "except the two people who wouldn't say anything." Adding to the cacophony was the local kaffeeklatsch yammering on the forum Topix and the crime addicts conjecturing on Websleuths.com.

bigflaw: I hope the police interviewed local sex offenders. I only found 2 from Star City on the WV Police website….

Pisces_Sun: Recently, there was an unconfirmed but possible sighting of Skylar in Carolina Beach….

Sparky: I tend to believe Skylar is alive, and in hiding from her parents.

From the get-go, Jessica Colebank's instinct told her that Shelia and Rachel were lying. A blunt 31-year-old Star City police officer with brown hair slicked back in a tight ponytail and dark, hawklike eyes, she was the first cop to interview them. "Shelia's demeanor was so off. I thought, If that were my best friend, I wouldn't be sittin' at home hanging out with friends having a good ol' time. I'd be bawling my eyes out and searching for her. Shelia was devoid of emotion, unless you asked questions she didn't want to answer. Then she could turn on the tears."

Rachel had already left for Camp Bosco, her Catholic church camp, so Colebank interviewed her on the phone. "Rachel was nonchalant, no panic, just like, 'I don't know where Skylar's at; you'll have to talk to Shelia for more stuff, 'cause I don't know anything else.' Their story sounded very scripted."

When Colebank interviewed Dave and Mary Neese, she came across Skylar's diary. While the teen hadn't written in it for a year—Twitter likely replaced it in her daily life—the journal illuminated the dynamics of the triangle. "A lot of her diary seemed…not jealous of Shelia, but Shelia had all the guys and could do whatever she wanted. Skylar was very pretty, but Shelia got all the attention. She made sure she got all the attention.

"Skylar wrote about Shelia's sexcapades—she didn't have any of her own," Colebank continues. "I think she lived vicariously through Shelia, because Shelia would tell Skylar who she did it with; how they did it; if it was good, if it was bad; if he was big, if he was small. I think that's one reason [Skylar] wasn't sexually active. She didn't need to be because she could live off the stories that Shelia was telling."

One entry in particular stands out. On August 21, 2011, Skylar detailed a night at Rachel's house when the three girls raided Rachel's mother's liquor cabinet. "They got drunk and Shelia and Rachel proceeded to make out in every way you possibly can outside of actually effing—and Skylar said the word," Mary says. "She was locked in the bedroom with them and afraid to leave, because Patricia [Rachel's mother] would find out they'd gotten into the liquor. So Skylar is having to sit there, watching them make out, because she didn't want them to get caught!"

Two weeks later Skylar tweeted: id tell the whole school all the shit i have on everyone, which is a lottttt #IfICouldGetAwayWithIt.

On October 2, 2012, Shelia posted this plea on the TeamSkylar<3 Facebook page, along with a picture of Skylar sitting on the floor with Shelia leaning back between Skylar's legs, eyes closed, as Skylar's kissing her cheek: skylar, sorry I havent posted in awhile school has been taking up all my time…me and Rachel miss you so much especially at lunch, we sit at a lunch table alone. come back so we dont look like loners anymore! lol school is so hard without you, actually everything is hard without you. I seriously think about you 24/7 and miss talking to you on the phone day and night. I know you wouldnt like some of the things that are being said lately.

Two people, using the pseudonyms JosieSnyder and Mia Barr, had started following Shelia and Rachel on Twitter and with obvious relish were taunting the girls. On October 10, 2012, Mia tweeted: Luke 12:2 Nothing is covered up that will not be revealed, or hidden that will not be known. On October 26, JosieSnyder wrote: @MiaBarr8 bring pretty little liars down together… #promisetoneverleaveyoucold. And a week later she asked: Whatcha gonna doo whatcha gonna doo when they come for you.

Attacked by vengeful digital spirits, Shelia fired off a tweet without a hashtag that was clearly a warning to all: no one on this earth can handle me and rachel and if you think you can you're wrong.

"Criminals have to let everybody know," says Chris Berry, a state trooper assigned to the case in mid-August 2012. "Back in the day, a murderer walked into a bar, had a drink sittin' beside a stranger, and said, 'Hey, I killed a guy the other night.' Now it's on social media."

West Virginia law enforcement got in on the game, creating an online persona. To flush out information, Berry says, "I portrayed myself as a fellow high schooler." At 29, boyishly handsome, wearing jeans, a long-sleeve white tee, and heavy boots, he could pass for one of the 30,000 West Virginia University students who swell Morgantown each autumn.

Berry scoured the three girls' Facebook pages "until I was passed out on the desk." Twitter, he admits, "was very difficult for me to read and understand. I only found out what a hashtag was six months ago. I thought it was called a retweet." What he gleaned from the accounts was that while Skylar was missing, Shelia continued to party on. "After 30 tweets about skipping school and getting drunk—'I miss you Skylar please come back home'—I'm thinking, Something ain't sounding right," he says.

At UHS, Rachel and Shelia were withdrawing from their peers. They were brought in again and again for questioning by the authorities, and each had a lawyer; they were the only people who did. "They were acting so weird and became a lot more secluded into each other," Hovatter says. "Honestly, I never liked Shelia—she was too controlling, always the queen bee, like, 'Bow down to me.' But Rachel was like Skylar to me; I loved them both. I told Rachel, 'If you know something, you better let the cops know, because they're going to find out. It's not a game.' "

Each time the girls were interviewed, it was like picking a lock, a tumbler falling into place, bringing the authorities closer to the truth. While Rachel would act "more reserved," says Colebank, Shelia was "very flirtatious." Berry recalls one day when Shelia strolled in wearing sweatpants rolled down below her pierced bellybutton and a bra-revealing cropped T-shirt, her long hair in a ponytail. "She was perky," Berry says. "I looked at Ronnie Gaskins [another state trooper on the case] and said, 'You gotta be kiddin' me.' "

They were trying to figure out the car mystery. "We watched the video and Shelia saw that car pull in and she said, 'I don't know whose car that is.' I was driving across the state bridge and it popped—I thought, Oh my God, you dumbass, it's Shelia's car! It had to be, because Skylar exited the window and never came back." What sealed it was a convenience-store surveillance tape that emerged showing a clear image of Shelia's car heading west toward the rural town of Blacksville, West Virginia, at a time when the girls had claimed to be driving east.

As the investigation progressed during the fall, the consensus among all the branches of law enforcement—local police, state troopers, and the FBI—was that Rachel and Shelia knew more than they were telling. Since phone companies don't keep a record of text message "literature," all the authorities had to go by were two pings off a phone tower near Blacksville—one from Rachel's phone and one from Shelia's, both after 4 A.M. on July 6—and changes in the girls' stories. FBI Special Agent Morgan Spurlock recalls Rachel's nonverbal cues: "She would play with her hair, clicking the button on a pen, or drawing on the table with her finger while we were trying to talk to her." Shelia, on the other hand, "had great posture, her hands folded on the table, she'd look you in the eye and speak matter-of-factly. She wanted to know what we were thinking, what we thought. And she would apologize for changing her story so many times. She would use excuses, like, 'It was late,' or, 'I wasn't keeping track of the time.' She would try to layer her perception of events that happened with a cloud of doubt over some of the facts that we could stick to her." He chuckles. "We sometimes don't even see that with the career criminals."

Shelia had taken a polygraph test and was confident she'd passed. "She was bigheaded. She thought she could beat it," Colebank says. On December 12, 2012, Rachel was headed downtown to take hers. But on her way to Gaskins' office, where a polygraph examiner was waiting, she panicked, jumped out of her father's car, and ran, winding up with Shelia's mother, Tara Clendenen. Police discovered this when Tara arrived at the Star City police station to pick up her daughter's electronics, which investigators had confiscated. When Colebank asked Tara if she knew where Rachel was, she replied, " 'Well, Rachel's down in my car,' " Colebank says. "That just pissed me off that she was helping them keep up their lives. Then she said, 'I wish you'd quit picking on my daughter. You're making her life hell.' And I was like, 'Good. I'm glad we're making her miserable because she is lying.' She got mad at me, and I called her a fucking tool." Colebank was kicked off the case.

JosieSnyder and Mia Barr, clearly connected to someone in the know, heckled the girls. JosieSnyder: oooh no no! Hiding from po po.

JosieSnyder: @MiaBarr8 failed lie detector.

Mia Barr: @_racchh Rach you know Shelia is pointng the finger at you!

Even Mary Neese posted a 1,600-word missive on the TEAMSKYLAR 2012 Facebook page: these girls are more guilty than originally suspected… it looks like foul play has occurred and murder has not been ruled out…. Within a day or two the post was taken down at the request of the authorities. But by then it had been forwarded ad infinitum.

Rachel and Shelia were finding the pressure from the police, the phantom posters, and the kids at school unendurable. Around winter break the girls began to be homeschooled rather than return to UHS. Then, on December 28, Monongalia County received a 911 call. "I have an issue with a 16-year-old daughter of mine. I can't control her anymore. She's hitting us, she's screaming, she's running through the neighborhood," Patricia Shoaf pants. In the background Rachel wails unintelligibly. Patricia says to Rachel: "Give me the phone. No! No! This is over. This is over!" And then to the dispatcher: "My husband's trying to contain her. Please hurry."

Rachel was admitted to the Chestnut Ridge Center, a mental-health facility. For the first time, she was beyond Shelia's reach, and Shelia's tweets—to whom, one wonders?—were no longer defiant. At 5:25 P.M. that day: wow literally worst night of my life.And at 10:32 P.M.: ugh hope my girl @_racchh is okay <3 loveee youuu.

On January 3, 2013, Shelia, who had tried in vain to see Rachel at Chestnut Ridge, posted a picture of the two at last reunited, smiling, with the caption: FINALLLLY GOT TO SEE @_racchh <3. In the photo Rachel looks strained, with good reason. She is wearing a wire. That day she'd gone from the hospital to her lawyer's office. He had called the U.S. Attorney's office and told them she was willing to talk to them if they could work out a deal.

"We were expecting her to say, 'Yes, Skylar overdosed on heroin,' " says Gaskins, who was the lead investigator in the case and one of the officials in the room with Rachel. "The first three words out of her mouth were: 'We stabbed her.' The agent and I were speechless for a little bit. Then we were like, 'Let's start over. Tell us exactly what happened. What do you mean you stabbed her?' "

Rachel pulled over a wastepaper basket in case she vomited and proceeded to recount the events in detail, unburdening herself of her sins.

Shelia and Skylar were always fighting. In the spring of 2012, Rachel and Shelia were in science class joking about killing Skylar when one of them said, 'We should kill her.' They gave each other a look of agreement and over the next month devised a plan they'd carry out before Rachel left for camp. Rachel took a shovel from her father's house. Shelia got two knives from her mother's kitchen. They put the shovel, cleaning supplies, and a change of clothes in the trunk of Shelia's car and drove to Skylar's apartment building.

Although the temperature that day was in the nineties, they wore hoodies, under which the knives were wrapped in rags so they wouldn't cut themselves. Once they got to Skylar's, they took the knives out of the cloths and put them back under their hoodies in the armpit area, to have them ready. They called Skylar, and she came out and got into their car.

Skylar thought they were taking a joyride, maybe driving out to Brave, just across the Pennsylvania state line, where they'd gone before and gotten high. She brought her bong and Rachel had her own pipe.

There at the edge of the woods, they found a place to sit. When Skylar got up to retrieve a lighter, Rachel said, "On three"—that was the agreed-upon signal, a count of one, two, three—and they began stabbing her from behind. At one point she got away, but Rachel tackled her. In the struggle, Skylar managed to get the knife from Rachel and cut her below the knee. But then Skylar was overpowered. "I asked Rachel what Skylar was saying," Gaskins says. "She said Skylar was saying, 'Why?' I asked Rachel the same question, 'Why?' Her response was, 'Well, we didn't like her.' "

this image is not available
Hellin Kay

After Rachel made her confession, she led the authorities out to the murder site, to find Skylar's body. Past Blacksville the snow became knee-deep, Gaskins says, and Rachel couldn't locate the exact area where they'd left her. The wire Rachel wore that night in an attempt to catch Shelia in the act of self-incrimination proved fruitless. Shelia must have known something was off. Thereafter, the girls' friendship devolved. The next day Shelia tweeted: first time ive ever been completely speechless…holy fuck. And on January 7: walk straight through hell with a smile. On January 15: you don't even know the amount of shit you have caused.

Then on January 16, 2013, a day bright with sun that melted the snow, Gaskins made the trip back out to Brave. This time, about 40 feet from the side of the road, covered with branches and debris, human remains were found, along with a cell phone in the wet grass. "There was an SD chip we could pop out that had photos on it," Spurlock says. "I sent it to the computer analysis people, and they were the exact same pictures on Skylar's Instagram account."

Because Skylar was, in the words of Monongalia County Prosecuting Attorney Marcia Ashdown "left…to nature," her head was no longer with her body. (Her skull was later found.) Skylar's remains were sent to the FBI's lab for definitive DNA testing, but Rachel, Shelia, and others seemed to know what was coming.

January 16, JosieSnyder: SKY is so gloomy today.

January 22, Shelia: wonder if there's a law and order svu where they DON'T figure it out.

January 28, Rachel: there's so much i regret but im on a new path and i seriously couldn't be happier.

February 2, Rachel: this bitch is not gunna ruin my life all over again -___-. And on March 8: my past is my past, move the fuck on.

On March 13 the news broke that the body in the woods had been identified as Skylar Neese's. Shelia went into survivor mode, sending out a series of tweets: the pain is real…. rest easy skylar, you'll ALWAYS be my bestfriend. i miss you more than you could ever know.

That day Rachel kept as quiet as the snow.

"People have asked, well, why weren't they arrested immediately?" Ashdown says. "Rachel had lied for months. Suddenly now she tells the truth? It looks believable, but you don't want that to be the only evidence that you have."

While the authorities built their case against Shelia—and worked to move the girls from juvenile to adult status—they struck a deal with Rachel. In exchange for her cooperation and testimony against Shelia, she would agree to plead guilty to a lesser charge of second-degree murder. Still shoring up their case, they allowed her to go on a vacation in April with her mother. On April 21 she tweeted a picture of a mimosa and: i need a mimosa…or ten.

Shelia spent her days living on Twitter, watching Law & Order: SVU marathons, attending the North Marion High School prom in nearby Farmington, and tightened her bond with a friend from near Blacksville, who'd been close to Skylar too. "Me, Shelia, Skylar, we hung out every weekend," says Shania Ammons, who attended Clay Battelle Middle & High School. "We were like a trio. I was equally close to them, but they were closer to each other. But when Skylar went missing, I got really close with Shelia."

On March 31, 2013, Shelia, as if goading the authorities, was tweeting back and forth with a friend about something unrelated, when she wrote: we really did go on three.

Throughout the month she tweeted what read like other veiled references to the murder:

April 23: if only you knew you'd shit right down your leg.

April 24: i hate when people blame their own actions and choices on others. deal with it.

April 27: ain't no rest for the wicked.

April 28: i hate seeing or hearing things that remind me of you because you're the last person i want to be reminded of.

April 30: i've closed enough windows to know you can never look back.

The next morning Spurlock and Gaskins pulled into the Cracker Barrel parking lot in Granville, West Virginia, as Shelia and her mother were about to get into their car. "She was more shocked than caught," says Spurlock. For 10 months Shelia had so often repeated and impressed upon others her version of events—to the authorities, to family, to friends, to Twitter followers—that she'd probably convinced herself she'd gotten away with the crime. Slapped into her new reality, Shelia was finally scared. "She said, 'Don't put me in with any mean people,' " Spurlock recalls. Ever the narcissist, she asked him if he had anything she could use to put her hair up. "Those are unusual requests, given the totality of the circumstances," he says. "She also didn't want to be seen in the back of the squad car: 'People can see me back here!' I said, 'Yes, Shelia, they can—you've been charged with first-degree murder.' "

The last movie to play at the abandoned art deco Warner Theatre in Morgantown was The Kids Are All Right. The grand old building is just down the street from the Monongalia County Courthouse, which is directly across from the Dollar General, where you can buy everything from Bibles to wine to underwear.

The courtroom of Judge Russell Clawges on January 24, 2014, was filled with spectators wearing purple—Skylar's favorite color. Mary Neese, resembling Elizabeth Taylor, with her black hair and azure eyes, was sitting in the gallery, a box of tissues at her feet. Dave sat next to her, holding her hand, his face as tight as a fist.

The audio system, rigged to accommodate the pressroom down the hall, was picking up a staticky radio station, so that Stevie Wonder sang "Isn't She Lovely" as Shelia Eddy, shackled and in an orange jumpsuit, white socks, and sandals, was sentenced to life in prison with the possibility of parole in 15 years. With the exception of "yes sir" and "guilty," the girl who'd sent 4,374 tweets had nothing to say for herself.

A month later Rachel entered the same courtroom, virtually unrecognizable: She'd gained weight, her skin was doughy, and her beautiful long red hair cut shorter. Everyone expected the actress to speak, and she did. "I am so sorry," she began, weeping. "I don't know if there's a proper way to make this apology because there are not even words to describe the guilt and remorse that I feel each day for what I've done. The person that did that was not the real me, not the person I am, not what I'm made of, and not what I believe in. I don't think I ever thought this would ever happen. I became scared and caught up in something that I did not want to do. I never realized the gravity of my actions"—at this Mary Neese flinched—"and how many people I have hurt. I hurt the Neese family and those who loved Skylar. I hurt my parents and shamed my family…. I hurt my teachers and those who believed in me.… And I hurt my Lord and savior Jesus Christ. May God bring eternal peace to Skylar and the entire Neese family.… And I pray each day for forgiveness."

Dave Neese spoke, haltingly, telling Rachel she could "take her apologies and everything else and sit on them because that's about what they're worth." Then Skylar's uncle, Michael Neese, came forward. "First day this all started…I made 200 flyers and drove…to the new Kroger.…I started passing them around to people walking out of the store, and I couldn't understand why no one would take any flyers from me. So I started putting them on windshields in the parking lot. A man stepped out of his car and he asked me if I needed help." Neese was crying. "I saw an older couple near their car, so I…handed them a flyer, and the man says, 'We're from out of town.' I just broke down, walked to my car, and went home." By the time he finished, much of the courtroom was in tears. The futility of xeroxed flyers in the age of the Internet was almost unbearable.

The last to speak for Skylar was the prosecutor, Marcia Ashdown. As she did at Shelia's sentencing, she recounted the events of that night, adding a detail, the image of which is unshakable: "Rachel Shoaf described the scene as having lots of blood…. Rachel Shoaf estimated that Skylar was stabbed 10 times before she died, and she explained that during the attack Skylar's…neck 'made weird sounds' and they both continued to stab her until those noises stopped…. Surely for this oh-so-adult crime of cold-blooded, planned, premeditated murder, there is no proper sentence other than an adult sentence."

Judge Clawges sentenced Rachel to 30 years, which, given the charge of second-degree murder, makes her eligible for parole in 10.

After all was done and said, there was the overwhelming sense that it wasn't over. No one—from the lawyers to the prosecutor to the investigators to the families involved—could square how three beautiful girls, best friends, could collide in such a violent event. "It's shocking to think what teenagers can be and how meaningless things take on ridiculous dimensions for them," Ashdown says. "Why in the world couldn't they just stop being friends with her? But then, some people kill their spouse rather than get a divorce, and it's not always about an insurance policy—it's that they want to kill them."

Romeo and Juliet, Endless Love, The Catcher in the Rye, A Separate Peace, The Fault in Our Stars…. Teenagers are as impulsive and passionate as the characters in their emotional bibles. What turned that passion, that fantasy—"We should kill her"—into reality was the merging of Shelia and Rachel's psychologies, intensified by the thrill of broadcasting their stories to a mass audience. "It seems like a game mentality, like they were proving something," says the Child Mind Institute's Howard. "It's not even about making sure someone's dead, it's about the act." One, two, three…. Were any one of the girls a different type, Skylar might still be alive. "Shelia would never have killed on her own," says Clemente, who is now a writer and tech adviser for the hit show Criminal Minds. "It took the two of them—sort of a dominant and a submissive—plus social media, which adds distance and anonymity. They had all this time to build up this plan and this fantasy, which was separated from Skylar."

To get some idea of just how big a role social media played in the murder, look at Shelia's phone records. "I've seen them," says author Daleen Berry (no relation to Chris Berry), a Morgantown-area resident who researched the case for the new book she coauthored, Pretty Little Killers. "Between July 4 and 10, Shelia wrote or received 5,215 text messages or phone calls. That means on average she was interacting with her phone 869 times per day—an inordinate amount of time with a machine."

It is without irony that Trooper Berry says, "I'm sure Shelia and Rachel will be hurting pretty bad in jail without social media. That was pretty much their life."

IT'S ALL ABOUT ME reads a sign on Skylar's bedroom wall. Over her iron bed frame is a picture of a dandelion, spent, ready for someone to make a wish. There's lots of purple in the room. "We've kept it pretty much the same," Mary Neese says. "Those are her Wendy's shoes." She points to the corner. "I tried to send her shirt and hat back, but they said, 'No, keep it.' She loved her job."

"This is the famous window, of course," Dave says, raising the blinds. "She just jumped down there and ran across and they were waitin' for her behind that building. I hope they hear her screaming 'Why?' for the rest of their lives."

Mary picks up Skylar's diary, which is dusty gray with an embossed heart in the middle. Most of it is written in pencil, in girlish print, her i's dotted with circles. "They asked us if we wanted her possessions, and I said, 'Yeah, I want everything I can get.' And I gotta admit, I was so, so hoping, just by some small inkling, maybe this isn't her stuff. But when I saw the bra, even caked with mud and leaves, I said, 'Yep, that's my baby's.' "

Skylar is everywhere in the lovely apartment with hardwood floors and sliding glass doors opening onto a deck overlooking the woods. She's smiling from pictures, drawings, collages, and a photo blanket draped across a chair. Pointing to her large framed portrait hanging on the wall, Dave says, "This is actually her urn. Her ashes are in the back of it." He holds up the thick cross around his neck. "This opens and her ashes are inside this, too." Mary wears her ashes as well, in a heart-shape locket.

"I want to show you something," Dave says, waving me over to the computer. He calls up the TEAMSKYLAR 2012 Facebook page. "This was taken at Skylar's site. My brother shot this video with his cellphone." He presses play and the camera scans the place where Skylar died, which has been memorialized with butterflies and balloons and flowers, and a wooden bench with the sign IN LOVING MEMORY OF SKYLAR A. NEESE 1996–2012.

Dave points to a swirling of clouds low in the sky, just above the purple heart of rocks; only they aren't clouds. It's more like a blur of energy, a mirage. "Right up here. See the mouth?" he says. "Hold on…two eyes, nose, mouth…. Now keep watching it. See? It's Skylar! See her smile? Those are her eyes. That's our baby. That's right where they found her. Right there. My brother didn't even notice it until he got home. He made me a copy and said, 'You ain't gonna believe this.' "

Mary rests her hands on his shoulders. Dave plays it again. "First time I saw it," she says, watching, "I just cried and cried and cried. It's like she's talkin'! It's crazy, isn't it? That's why we have made that site where it is, like a little park. She seems happy there." Dave brushes a finger across the screen, across Skylar's cheek and says, "See her smiling? She loves it there."

This article appeared in the September 2014 issue of ELLE magazine.