(CNN) -- Lauren Astley knew her ex-boyfriend was having a hard time getting over their breakup.
Nathaniel Fujita hadn't wanted to end their three-year relationship. He made it clear in a long e-mail, asking her to give him a chance to find "a part of you that still loves me." But after several "negotiated truces," as her mother calls them, it was over in May 2011, a few weeks before their graduation from Wayland High School in Massachusetts.
But Lauren, 18, didn't stop worrying about Nate, especially as he withdrew from his friends. She was known for being kind, caring and deeply involved in the lives of friends -- attributes her classmates lauded in her senior yearbook, along with her singing voice and warm smile. She discussed her ex-boyfriend's antisocial behavior with friends, and they decided together that she should be the one to reach out to him. After weeks of ignoring her texts, Nate, 19, finally agreed to meet her on July 3, 2011.
The next day, her body was found in a marsh about five miles from his home. He had strangled her with a bungee cord, stabbed her multiple times and slashed her throat. Her body was dumped in a nature preserve he knew from science class.
Nate had shown signs of jealousy in the past, but nobody suspected he would hurt Lauren. During his murder trial, his lawyer said he snapped mentally when he killed her. Prosecutors said it was a case of extreme dating violence, that he wasn't psychotic -- just angry, hurt and humiliated by the breakup.
Nate was convicted of first-degree murder in March and sentenced to life in prison. But the quest for closure doesn't always end with a jury's verdict, especially in places like the couple's hometown of Wayland, which calls itself a "stable and progressive community, characterized by a legacy of civic engagement."
It's the kind of idyllic American suburb where "things like this aren't supposed to happen." In the wake of her death, community members pondered the warning signs. What did we miss? Could anybody have stopped this before it spiraled out of control?
Lauren's family saw new meaning in their "typical teen" drama: the fights, the constant cycle of breakups and reunions, the young man's retreat from social life after the breakup.
But as the couple's case shows, the line between adolescent drama and dating violence is a hard one to draw, especially in the moment.
Finding a new normal
Questions about what could've been done differently arose recently in Steubenville, Ohio, in Torrington, Connecticut, and in other communities where teen dating violence and sexual assault drew national attention. Blame bounces around the victim's clothes, the amount she drank, whether she "put herself in that situation," and to the perpetrators, parents and society for fostering a culture in which violence among teens -- sexual and otherwise -- makes regular headlines.
The Steubenville case, in which a teen was sexually assaulted as others watched, revived discussion around the importance of bystander education -- teaching people to intervene safely in behavior that promotes sexual violence, said Tracy Cox with the National Sexual Violence Resource Center.
School violence prevention programs typically focus on risk-reduction by teaching girls not to be victims and boys not to be rapists, with no other roles to play. Even though bystander intervention is not a new concept, some schools, advocacy groups and corporations are pushing it with renewed vigor in an effort to deter violence.
The goal is to challenge perceptions of "normal behavior" and make teens aware of the nuanced interactions that create a hostile climate. It could be as simple as diverting a friend's attention when he hollers at a girl on the street, encouraging your sister to talk to her boyfriend instead of secretly checking his texts, sneaking off to call 911 when the popular guys start messing with a girl who's barely conscious.
"Bystander intervention gives everyone a role to play in preventing relationship violence," said University of New Hampshire psychology professor Victoria Banyard, whose research has examined bystander intervention in relationship violence prevention programs.
"Chances are, you have a friend, brother, sister or neighbor who will be affected by relationship violence," she said. "The question is, how good of a friend, brother, sister or neighbor are you going to be?"
Schools have taken on the work of teaching adolescents about substance abuse, sex and in some cases, preventing dating violence. And it works. Evidence shows that classroom education based on lectures and activities can help, as well as programs that enlist coaches to talk to high school athletes about dating violence.
It takes more than classroom education to change cultural norms, Banyard said. It requires community intervention, marketing and government policies, much like the fight to change perceptions of drunken driving and smoking.
"You can change people's behavior, but it doesn't happen overnight," Banyard said.
It starts first by acknowledging that dating violence is a community problem, analyzing risk factors and talking about them, said Emily Rothman, an associate professor with Boston University's School of Public Health.
Research shows that parents are less likely to talk to children about dating abuse than school, drugs, alcohol, the economy, even dating and sex in general, she said -- despite the fact that it's just as prevalent as frequent cigarette smoking and driving while drunk, she said.
That needs to change.
"The problem is when we look at incidents like this as random acts of craziness instead of dating violence," she said of Lauren's death.
Some risk factors might seem obvious, like groping, stalking or other sexually aggressive behavior, Rothman said. But research shows that an influential factor in dating violence is associating with peers who project negative attitudes toward their partners through actions or words, she said.
Lauren's parents say there's no reason to believe that Nate physically or sexually abused their daughter in a manner straight from the script of a made-for-TV drama.
But they were dating, and he killed her. As far as the law and public health norms are concerned, it was a case of dating violence.
Nate's family doesn't see it that way. To them, Lauren's death was a tragic consequence of mental illness, not the result of dating violence.
His parents declined to be interviewed for this story. His lawyer, William Sullivan, told jurors in his trial that the teen suffered from severe depression. A forensic psychiatrist testified that his family was aware of his struggles with depression and sought treatment when his grades began to suffer during his senior year.
"According to testimony, the Fujita family, in fact, did not ignore signs that he needed help; they did everything they could to help him," Sullivan said in a phone interview.
Regardless, educators, parents and students around the community where Lauren was raised decided to make a change.
Knowing when to speak up
The impact of Lauren's death reverberated through her hometown, down Boston Post Road to the home of Wayland's rival, Lincoln-Sudbury Regional High School, or "LS" as it's known.
Students from the two schools grow up together, just three miles apart on a congested two-lane road between their once-rural exurbs. They play each other in sports, compete for roles in community theater productions and hang out in the same Dunkin' Donuts after school.
Lincoln-Sudbury students know Water Road, the tree-covered path that loops around the nature preserve near their school. When runners and lacrosse players jog, they pass near the marsh where a local resident spotted Lauren's knees popping from the brackish water the morning of July 4, 2011.
"Lauren's death could've happened to a student at LS," said Sam Chen, who's graduating from Lincoln-Sudbury this year, bound for Amherst in the fall to play lacrosse.
A National Merit Scholar finalist and co-captain of the champion lacrosse team, Chen added to his busy schedule this year by joining the school's "Mentors in Violence Prevention" team formed in response to Lauren's death.
The program was developed in 1993 at Northeastern University's Sport in Society. It enlists student athletes and leaders to speak out against sexual harassment and other forms of abuse typically considered "women's issues."
"People, especially teens, think there's only one way to respond to a tense situation, either by sticking their necks out or doing nothing at all. There are a lot of options in between," said Safe Schools Coordinator Lori Hodin, who helped start the program at Lincoln-Sudbury.
Male and female student athletes participated in daylong training sessions using the "MVP playbook," which employs sports terms to discuss scenarios from the minefield of adolescence. Hodin and four faculty facilitators led discussions on ways bystanders could respond, and how to recognize themselves as potential perpetrators.
The scenarios range from gang-rape and drunken come-ons to street harassment and gay-bashing. After "running the plays," students said they realized they witness warning signs of troubled relationships every day in the halls of their high school.
They seem meaningless on their own, but they add up to a disturbing trend, said John Sexton, a rising senior who plays lacrosse and football.
He knows girls and guys who are overly protective of their partners to the point of being possessive, he said. They keep tabs on their partners through social media and constant texting. They overreact if they don't get a response within minutes.
The training showed Kimberley Heller, a cheerleading co-captain starting at U.S. Naval Academy this month, how she could have responded differently to a past relationship. She stayed with a boyfriend her friends called "annoying and clingy," despite his insistence that she spend all her free time with him. When she broke it off, he threatened to kill himself, texted her hundreds of times and followed her around school. She eventually requested supervision from school staff.
She stuck around despite signs that the relationship wasn't a good one, she said. If she knew then what she knows now, she would've ended the relationship as soon as he started trying to control her, she said.
"MVP has given me the confidence to speak up for myself and to talk to my friends about relationships," she said. "If bystanders can learn to be comfortable speaking up, it will go a long way in the community."
The students said they rarely intervene in physical or sexual abuse. But even in their relatively safe, sheltered middle-class communities, they still see reasons to step in where they might have stayed silent before.
The most common hostile scenario they encounter is the locker room. It's a high concentration of young guys, no girls and little adult supervision. MVP team members said they're trying to change the language and tone of "trash talk" to make people think twice about calling someone a bitch, a fag or even joking about sexually aggressive behavior.
It comes up often, Chen said. Recently, he called out a teammate for talking about what he'd like to do to a girl who passed by during football practice.
"C'mon man, that's not cool," he responded.
Another favorite response of his: "What if that was your sister or mother?"
It resonated with him during training, and compelled him to stick with it.
Not everybody the school invited to MVP followed through. It takes a lot for teens to reject a lifetime of cultural programming, to suddenly tell teammates what's not OK, or to call the cops on friends when a party gets out of hand.
But several who stuck with it described a catharsis or awakening.
"We've learned the power of sharing lessons and talking to your peers," Sexton said. "It's our role to talk about these issues and share them with others."
On a cold, rainy evening in April, about a month after Nate was sentenced, the MVP team gathered in a classroom to run through some of those lessons.
As they rolled in after sports practices and games, they were an unmistakably athletic crowd -- confident expressions, strong builds, a wardrobe of sweats, Under Armor and Lincoln-Sudbury Warriors varsity jackets.
The group planned to perform at a school assembly where they would demonstrate healthy relationships and bystander intervention. But this time, they wouldn't use made-up stories or examples.
Instead, they'd use details from the Steubenville rape case, and from Lauren and Nate's relationship.
"We want to focus on what was overlooked and how people could have responded differently," Chen explained as the students took their seats.
Students followed along on their phones as Chen went through the presentation slides, beginning with pictures of Lauren and Nate.
"Just looking through these pictures shows that Lauren and Nathaniel were normal high-schoolers, in what seemed to be a healthy relationship," Chen read aloud. "They went to prom, participated in normal extracurriculars, and they were looking forward to an exciting four years in college. They had a bright future, just like all of us here. But something went wrong, and their relationship became abusive.
"So what happened? What is abuse? What are the warning signs, and how can we, as high school students, ensure that such a tragedy never happens again?"
Chen read aloud, defining dating abuse -- any behavior that one person uses in a relationship to gain and maintain control over their partner -- and the forms it comes in: verbal, physical, emotional-psychological and sexual.
He showed another slide that said, "Maybe they could've taken action." It included a photo of Lauren and her friends, arms locked.
Chen looked around the room for feedback
"It's risky to directly tie Lauren's friends to the warning like that. It might sound like we're saying they didn't do enough," one student volunteered.
Together, they decided to swap the picture for a shot of Lincoln-Sudbury students and to make the language pronoun neutral.
It's a question the students struggle with, and a criticism the bystander theory faces: How can anyone tell when it's appropriate or safe to get in someone else's business? Where's the line between an overreaction and preventing a murder?
Learning the warning signs becomes important, Lincoln-Sudbury senior Paul Sorbo said, so people have "the critical thinking skills necessary to make those calls."
"We're fighting the underlying causes of what allowed that situation to get as extreme as it did. By getting this sort of training, you start picking up on things that fall into the gray area."
Heeding warning signs
Lauren and Nate were together throughout most of high school, a picture-perfect couple from the moment they started dating freshman year. He was a tall and handsome football player who impressed her father with his grace and humility on the field. She was nearly a foot shorter, with piercing green eyes -- the popular girl who was nice to everyone and seemed to excel in everything she tried. She was the captain of the tennis team who won the lead role in a local theater production of the musical "Annie" without any theater training.
But trouble stirred beneath the surface. None of Lauren's friends liked her boyfriend, said Lauren's mother, Mary Dunne. He was jealous and prone to violent outbursts, like when he hit a boy she danced with and kissed at a 2009 party, when they were on a "break." He once broke a windshield and punched holes in his family's living room wall, Dunne said, although the jury in his trial never heard that. Such evidence would be more prejudicial than probative, Judge Peter Lauriat ruled, given how much time passed between them and Lauren's death.
Malcolm Astley, Lauren's father, said it would be easy to dismiss Nate as a "monster." Instead, the retired high school principal is trying to learn from his daughter's death and find ways to prevent more tragedies. As a father and educator, it helps him cope.
Nearly two years after her death, evidence of the petite, fair-skinned teen remains strewn throughout the home; a pair of black high heels rests among her father's shoes near the door; framed class portraits and pictures with friends adorn walls and tables.
Lauren's teal-walled bedroom is in almost the same state she left it on July 3, 2011, bearing signs of the childhood she was leaving and the young woman she was becoming. A cutout picture of The Little Mermaid is tucked behind a stack of ELLE magazines on her desk, below a bookshelf of children's classics, "Little Women," "Matilda," "Where the Sidewalk Ends."
"A breakup is one of the most traumatic events we go through, regardless of age," Astley said, but they're especially hard in the summer before college, a major turning point.
Maybe if there were other ways and other people to help his daughter's ex-boyfriend, it would've made a difference.
"The point is not to demonize anyone, but to analyze the signs and determine who could've been in place to help," Astley said.
His daughter could have acted differently, too. He wishes she'd had "the courage to be cautious," to consider for a moment that it wasn't up to her to heal her boyfriend.
"She was a spunky kid and that can be disadvantageous if you're not alert to the harsh potential consequences," he said. "It's great to have confidence, but if it prevents you from being alert and knowing there are things that can happen to you, that's a problem.
"We can do a better job of instilling that caution without making our children panicky or distrustful of everyone."
Astley said he has tremendous sympathy for the Fujita family, too. In the minutes after Nate was sentenced to life in prison, Astley crossed the courtroom aisle and shared a long embrace with the defendant's parents.
Learning from tragedy
Lauren's father doesn't claim to understand what led Nate to kill his daughter. But he wants to ensure that other teens have ways to deal with grief.
Astley, Dunne and Lauren's family friends launched the Lauren Dunne Astley Memorial Fund, a nonprofit dedicated to educating the public on healthy relationships and dating violence through a variety of programs and legislative action.
In May, Astley and Dunne testified at a Massachusetts House hearing in favor of bills that would mandate sexual education and violence prevention programs in Massachusetts schools.
The fund paid for several productions of "The Yellow Dress" a one-woman play about dating violence, including a performance at Lincoln-Sudbury as part of the MVP assembly.
Before its own presentation in April, Lincoln-Sudbury's MVP team consulted with Astley about dating violence and bystander prevention. They studied news coverage of Nate's trial, looking for subtle warning signs.
They drew upon the e-mail he wrote to Lauren, saying, "I truly think there's a part of you that still loves me, you just have to let me find it." They talked about a graduation party in June, after the breakup, where the couple saw each other, how Nate followed Lauren and became belligerent and disruptive. When Lauren told him to leave, he grabbed a tent pole, nearly causing the tent to fall.
They told an audience of their classmates that seemingly sweet words revealed a need for control. They described how physical abuse doesn't have to be a direct blow. They said any act of aggression meant to harm a partner, whether physical or emotional, counts as abuse.
"Nathan's assertion of dominance escalated throughout the teen's relationship," an MVP student said. "This is a warning sign."
But it takes more than a single assembly to get through to people, young and old. After all, MVP had existed at Lincoln-Sudbury before, for about a year after the 2007 stabbing death of a student by another teen, then lost steam after participating students graduated.
It's a pattern that mirrors the way society deals with tragedy: outcry and action that peters out until the next tragedy revives the sense of urgency.
The challenge for Lincoln-Sudbury now is to keep the audience filled, to institutionalize the changes they want to see in the culture, Hodin, the Safe Schools Coordinator, said. They selected juniors to be part of MVP team at Lincoln-Sudbury, and she hopes the April assembly keeps up momentum.
Some things changed, too, at Wayland High School, where Lauren and Nate met as freshmen. Bystander education is now part of the curriculum for ninth-graders, instead of 11th-graders. Teachers also receive a day of training each year on how to spot and respond to unhealthy relationships. This year, the course focused on ways to discuss healthy relationships outside of class by scrutinizing pop culture lyrics and popular media in music and English classes, for example
At the advice of the school psychologist, principal Patrick Tutweiler didn't tell students directly how to mourn Lauren; they waited for students to come forward with ideas on how to honor her memory. It resulted in the Lauren Astley memorial mosaic that hangs in an outdoor common area.
There's no handbook for school administrators on how to deal with the death of student, Tutweiler said. It certainly wasn't covered in his doctoral studies.
But schools can't afford to wait until the next tragedy, he said.
"All schools should be doing this," he said. "It's an important part of students' education."