PALM BEACH GARDENS, Fla. — It took several minutes for Assistant State Attorney Gregory Schiller to get all the eighth-graders inside the Watson B. Duncan Middle School gym to put their heads down. Even then, a few adults hesitated.

“You too, sir,” Schiller said. “Yes you _ even all the teachers, I want everyone’s heads down and eyes closed.”

Once he got what he wanted, Schiller _ who has prosecuted hundreds of people locally for committing online sex crimes _ asked the teens to raise their hands if they’d ever sent or received a naked picture of someone 16 years old or younger.

The secret poll is an original twist Schiller has added to his presentation over several years he’s spent speaking to teens, school officials and parents about the dangers of online predators and “sexting,” the practice of sending naked or explicit photos through cell phones or online.

In a time where many schools are waging war against issues like bullying, Schiller and other online sex crimes prosecutors say sexting has become a silent epidemic that has spread beyond high school to middle and even elementary schools.

On this day, for example, in the auditorium full of several hundred 13- and 14-year-olds, Schiller estimated 50 hands went up in response to his blind survey. The actual number is probably higher, Schiller says, because teens typically underreport sexting.

After the students and teachers raised their heads again, Schiller matter-of-factly told them that the children who raised their hands were likely all guilty of committing a felony. It is illegal to send or receive naked photos of underage children, even if the sender or recipient is also underage.

The revelation brought wide-eyed stares, gasps and oohs from the crowd of teens. A girl seated near the front of the auditorium, her hair folded into a long fishtail braid, covered her eyes with her hand later as Schiller played a video depicting what could happen if a young girl sent a naked picture to her boyfriend.

In the scenario Schiller played, the boyfriend fowarded the picture to a friend, who sent it to other friends and the picture eventually got back to the girl’s little brother, her mother, and a shadowy stranger the video narrator later identified as an online predator.

Schiller, part of the State Attorney’s Office Special Victims Unit, says he plays the video to show the students that what they think is a private image shared with one person is something they forever lose control over once they press send.

He uses words like “sexting” with eighth graders because they’re all headed to high school, but he is much more guarded with sixth graders and elementary school kids, avoiding the word “sex” altogether while warning them to stay away.

And because Schiller constantly deals with online predator cases, he knows all the latest trends on how children use social media. In this presentation, about half of the students Schiller spoke with had Facebook pages, and many of those were active before they were 13. Even more of them had their own Twitter accounts, and nearly every hand went up when Schiller asked how many of them were on Instagram.

These are all places, Schiller warned, where online predators can befriend and eventually take advantage of them.

“No matter how tough you think you are, no matter what army you think you have behind you, you cannot handle what is going on out there,” Schiller told the group. “It is overwhelming, it is intimidating, and it will ruin your life.”

Schiller should know. He’s handled cases where local defendants from all walks of life have sent, received or produced photos and videos of children objectified and brutalized in ways unfathomable to the general public.

Though he’s spoken to tens of thousands of students over the years, he’s tried to fit in as many presentations as he can over the past several weeks, hoping to educate as many local children as he can before they go on Christmas break and have ample time on their hands to potentially fall prey to victimizers.

Schiller says parents can keep their children safe from online predators by keeping all computers and electronic devices in public areas, turning off wifi signals at bedtime and opting to buy more traditional flip phones instead of smartphones.

Duncan Middle Principal Phillip D’Amico said he heard Schiller’s presentation several weeks ago and was “blown away” by how widespread the problem has become.

With each presentation, Schiller makes sure to hammer home the ultimate point that when it comes to what people do online, nothing is secret.

“I’m the one at the end of the road who you’ll meet if you’re a victim or you’re being prosecuted for one of these crimes,” he said. “So let’s talk about it now, before we get there.”