A former teacher at H.B. Beal Secondary School in London, Ont., was sentenced Tuesday to six months in jail and 12 months probation for secretly recording female students' breasts and cleavage, using a pen camera.

Between 2010 and 2011, Ryan Jarvis made recordings of at least 27 students, most of whom were as young as 14. The videos, which ranged from six seconds in length to more than two and a half minutes, were captured during conversations he had with students in common areas such as the cafeteria and hallways.

Tap to hear the CBC's Amy Dodge explain the case on Afternoon Drive.

Some of Jarvis's victims were in court Tuesday to hear the sentence. ​​​​​​

In 2015 the trial judge determined that Jarvis had violated the students' privacy by using a spy pen. But Justice Andrew Goodman wasn't satisfied the videos were filmed for a sexual purpose and acquitted Jarvis

Ryan Jarvis was a teacher at H.B. Beal Secondary School when he was found recording students' breasts with a pen camera. (Thames Valley District School Board/tvdsb.ca)

The Ontario Court of Appeal went another way. Most of the judges on that bench ruled that Jarvis did act with sexual intent, but still upheld his acquittal, arguing the students had no reasonable expectation of privacy at school.

But the Supreme Court of Canada found unanimously in February that Jarvis was guilty of voyeurism and, in a landmark ruling, determined people can have a reasonable expectation of privacy in public spaces.

The Supreme Court said students doing everyday activities at school don't give up their privacy rights — even if the school maintains security cameras.

During sentencing, Superior Court Justice Andrew Goodman said that he wanted to send a message about the use of mobile phones and taking photos.

Victims in court

Nearly a decade after Jarvis was charged, some of the victims were in court to hear the sentence.

"I don't have the words. I've waited so long for him to finally get not only found guilty but to get sentenced for what he did to all of us. I don't even want to say it's a win, it's almost just like a breath of fresh air," said one victim, who cannot be identified because of a publication ban.

Some of the victims have followed this process through the court system for more than four years and said a sentence brings relief.

"It's finally done, and I've been fighting for it to be done," said one woman. "I'm OK with six months. It is a lot more than I was expecting him to get."