The video was posted on a social media site on April 5 following a party at a Halifax residence and investigators became aware of it three days later, Const. Pierre Bourdages said.
"This is very unusual," Bourdages said Wednesday. "It's not something we've seen lately. It's very troubling."
Bourdages said the sex was consensual but the accused posted a video of the act without the girl's consent. Investigators believe he acted alone and while the two youths knew each other, Bourdages wouldn't comment on the status of their relationship.
Officers seized a cellphone following a search of a Halifax home on May 2 and the accused turned himself in on May 24, Bourdages said. The site quickly deleted the video from its servers but police don't know if other copies exist, he added.
Criminal law and social media experts say they believe the case reflects the growing use of the Internet among teenagers for increasingly destructive acts.
They also say it shows police and prosecutors may be trying to send a strong signal that the victimization of young women won't be tolerated.
Robert Currie, a professor of law at Dalhousie University in Halifax, said police have hesitated to prosecute such cases in the past, preferring a stern lecture and a warning. He cited a case in December 2011 where police responded to the distribution of photos of naked young people at a high school in Sydney, N.S., by speaking to parents and launching an extensive education campaign.
"What this might indicate is we have more willingness to charge," he said. "The perspective police had been taking up to this point was to try to educate."
Wayne MacKay, an expert on cyberbullying and also a law professor at Dalhousie University, said police may be partly motivated by the case of Rehtaeh Parsons. The 17-year-old Halifax girl died in hospital after hanging herself in April.
Her parents say she was sexually assaulted by four boys in 2011 and a photo of the alleged incident was passed around her school.
"I think one of the factors in the background is the high profile of the Parsons case and the fact the police were criticized for not going as far as they should in that case," said MacKay.
Police originally said there was insufficient evidence to lay charges in the Parsons case, but their investigation was reopened days after the girl's death when they said they received new and credible information.
Bourdages said the Parsons case didn't play a role in the decision to prosecute in this case. He said each case is dealt with on its own merits and in this instance, officers felt the alleged actions and evidence strongly supported charges.
"As far as we're concerned, we have to take a file where the evidence leads us," he said. "In some files, the evidence is not there. Where there is evidence ... charges will be laid."
MacKay, who wrote a report on bullying for the provincial government that called for an emphasis on education programs and prevention in schools, said the charges may be justified. But he said it's unclear whether the case will deter other young people.
"There needs to be more education in these matters," he said. "It will be interesting to see why this more extreme approach was followed in this case."
Jacquie Burkell, a professor with Western University in London, Ont., said the harm to young women whose sex acts are videotaped without their knowledge is severe.
"It causes shaming," said Burkell, who works at the school's Faculty of Information and Media Studies. "We have numerous, high-profile cases where the shaming led to suicide."
The boy is scheduled to appear in Halifax provincial youth court on June 20 on charges of possessing, making and distributing child pornography.
Neither teen can be named under the Youth Criminal Justice Act.