Fairfax County Public Schools are now teaching students about sex assault and consent as part of its family life education curriculum. This video is proposed for use in high school. (Human Relations Media)

The educational video opens with a sober warning: Those who rape and sexually assault are not always predators hiding in the shadows; they sometimes are those closest to you.

“My idea of rape was someone snatching me up in an alley, a dark alley, a stranger, not someone that I date, not someone I trust,” a young woman and survivor of sexual assault says as the video — “Defining Sexual Assault” — begins to walk students through the challenging subject.

This might be the kind of lesson you’d expect on a college campus as the nation continues to respond to the deep and growing concern about sexual assault. But in Fairfax County, Va., one of the nation’s largest public school districts, the video is a proposed part of a new sexual education curriculum designed to teach teens about consent and assault before they graduate from high school.

Fairfax County Public Schools last year updated its family life education curriculum to include lessons on sexual consent and more thorough instruction on sexual assault, and the changes are slated to be implemented next school year. They are topics that have been widely addressed on college campuses, often as part of freshman orientation, but there is a growing belief that the education needs to come earlier so that it becomes second nature to young people. The main federal education law, updated last year, requires high schools to report how they are teaching students about safe relationships, including consent.

Elizabeth Payne, who oversees Fairfax County’s family life education curriculum, said the wave of news about sexual assaults on the nation’s college campuses during the past few years has disturbed her. Numerous polls and surveys, including one last year from The Washington Post and the Kaiser Family Foundation, have shown that approximately 1 in 5 women say that they were assaulted during their college years.

Payne said she believes health educators have a role to play in addressing assaults.

“We knew it was time to do something about it,” Payne said.

College sexual assault has been gaining national attention, largely through a series of high-profile cases at major universities. Most recently, there was a public outcry after Brock Turner, a former Stanford swimmer convicted of sexually assaulting an unconscious woman outside a fraternity party, was sentenced to six months in jail instead of the multi-year prison term prosecutors were seeking. The case underscored for some the importance of consent, especially in an environment where people are drinking or using drugs to excess.

After Turner’s conviction in March, Santa Clara County, Calif. District Attorney Jeff Rosen said he hoped the case drove home a message that “will clearly reverberate throughout colleges, in high schools, anywhere where there may be any doubt about the distinction between consent and sexual assault.”

“No means no, drunk means no, passed out means no, and sex without consent means criminal assault,” Rosen said, according to several local news reports .

By the time high school graduates arrive on college campuses, many of them have conflicting ideas about what constitutes sexual consent, a Washington Post survey found, and many of them never learned about it before getting there.

Anjali Khanna, 18, a senior at Fairfax County’s Thomas Jefferson High School for Science and Technology magnet school and founder of a student group to combat sexual assault, said the education on consent should not be delayed until college.

“The more we talk about this, the more ingrained it becomes in our societal attitudes,” said Khanna, who is bound for the University of Virginia.

Views differ on whether it is appropriate to teach such topics in class. Some parents think that families — not schools — should be in charge of teaching children about sex, including sensitive topics such as consent and assault, so they can tailor lessons to their values and beliefs.

Meg Kilgannon, a mother of three Fairfax County high-schoolers and a middle-schooler, said she opted her children out of family life education because it lacks “any discussion about your sexuality as an expression of love for another person.” She said sexual assault and consent should be taught in the home: “These are extremely personal topics.”

But Amy Morgan, a mother of three elementary school students, said she supports teaching sexual consent in high school because “there are a lots of cultural messages that are contrary to this idea of consent.” She said she thinks that schools should teach the general concept of consent — outside of the context of sex — in even earlier grades.

“I talk to my kids about ‘no means no,’ if you’re wrestling or even if you’re playing a game and someone’s not having fun,” Morgan said.

Andrea Hummel, whose daughter is in high school, said she hopes that girls will learn that it’s okay to set boundaries — and that boys will learn to listen.

“I think that girls don’t realize that it’s okay to say ‘no,’ ” Hummel said. “Clarifying for the kids what constitutes sexual assault versus consent is important.”

Del. Eileen Filler-Corn (D-Fairfax) authored a bill that would have amended the state’s family life education standards to include lessons on sexual consent in addition to “programs on the prevention of dating violence, domestic abuse, sexual harassment and sexual violence.”

But lawmakers stripped language on consent from the bill, which Gov. Terry McAuliffe (D) signed into law last week. The new law requires schools to teach about sexual harassment but might have little effect on what is taught in the classroom; state standards already require lessons on sexual assault. The state also does not require schools to offer sex education.

The proposed curriculum in Fairfax County schools would include a three-part video that features interviews with three women who said they were victims of sexual violence and input from several experts, including a psychologist, social worker and a nurse who has worked with victims. The school board is expected to vote June 30 whether to include the video.

The video describes consent as “healthy communication between the two people who are involved,” emphasizing that someone who is intoxicated, unconscious or sleeping cannot give consent. It also teaches that silence is not the same as consent.

“It’s like expressed permission that what’s happening right now is equally cool to the both of us,” psychologist Robert Eckstein of the University of New Hampshire says in the video.

The video also approaches the fraught subject of what young people can do to reduce the likelihood of being sexually assaulted, an approach that has often been cast as victim-blaming.

“I think it’s tricky to talk about telling young people not to drink or not to leave a party alone because there is a sense of blaming the victim, right? The onus is always on the perpetrator,” Amy Edelstein, a licensed social worker, says in the video, narrating over an image of silhouetted young people at a party. “But I think there are situations that maybe put people at more risk. Making good choices, staying together in a group obviously can be helpful, but it doesn’t mean it can prevent sexual violence from occurring.”