Officials at several Baltimore-area schools are warning parents that someone has contacted students through social media, using what police called sexually explicit language and images.
The person engaged two teens who attend St. Paul's School for Girls — ages 15 and 17 — in video chats and communications that included explicit "conversation and images," according to Baltimore County police spokeswoman Elise Armacost.
Police initially said the person is male but that they had not determined his identity or age. On Tuesday, they said the person appears to be male on social media, but that they could not confirm the gender. They say there is no indication the person tried to physically meet the girls.
Armacost said police have not yet even determined whether a crime has occurred. That depends on factors such as whether the person who sent the messages is an adult.
"The mere act of sending sexually explicit information is not necessarily a crime," she said.
The episode has left parents and staff at St. Paul's and other schools on alert in a situation authorities say underscores not only the need to talk to children about online safety but also the perils that exist in an ever-changing world of social media.
Penny B. Evins, head of the St. Paul's School for Girls in Brooklandville, sent a letter to parents last week saying a person she called a "sexual predator" contacted students via Facebook, Instagram, Vine and Snapchat. She called it a "serious and potentially dangerous situation."
In her letter, Evins said the person has contacted more than 50 upper-school students at St. Paul's.
Gilman School, a Roland Park private school for boys, told parents in an email Monday that "a small number of Gilman students ... have been approached by this person online."
After Evins' letter, other schools — including Maryvale and Notre Dame preparatory schools, St. Paul's School, Friends School, Garrison Forest School, the Park School of Baltimore and the Bryn Mawr School — also sent letters to parents telling them what happened to the students at St. Paul's School for Girls.
Baltimore County Public Schools have not received reports of anyone targeting students in that system, a spokeswoman said, but one public high school in the area, the George Washington Carver Center for the Arts and Technology in Towson, shared information with parents about the incidents.
Baltimore public schools have not received reports of an online predator targeting students there, a spokeswoman said.
According to Evins' letter, two girls at the private school in Brooklandville told administrators about the communications. Evins contacted the girls' parents and police, who launched an investigation. She also gathered upper-school students together to talk about social-media safety.
"At this point, all our students are safe," she wrote. "We will remain vigilant."
Police could not confirm that 50 students had been contacted at St. Paul's School for Girls but said one girl accepted a "friend" request and a request for a video chat from the person in summer 2012. The other girl was contacted last week.
Richard Guerry, executive director of the Institute for Responsible Online and Cell-Phone Communication, a New Jersey-based nonprofit, said it can be difficult for parents to keep up with changing technologies, but basic guidelines can help keep them safe.
"A lot of parents, they know what Facebook is, and they know what Instagram is, but they don't know about things like Snapchat," he said, referring to a mobile texting application that deletes pictures and messages after 10 seconds. "There's absolutely no way to know every single application that your kids are using."
Guerry gives talks to students and parents about online safety and is scheduled for a presentation this week at Notre Dame Prep. He said his organization's mantra is that all online activity is "public and permanent."
"The goal is to limit the amount of information that a complete stranger would be able to find," he said, including phone numbers and details about daily routines. "Too many people have this false expectation of privacy."
Armacost called the St. Paul's School for Girls incident an "opportunity for us to stress the importance of parents educating their children on social media use."