An 18-year-old made his first court appearance in Lethbridge Monday after being charged with uttering threats against a southern Alberta school.

John Clapham was arrested on Boxing Day.

Police allege he made comments on Facebook that referenced the Sandy Hook Elementary shooting in the U.S., which claimed the lives of 20 kids and six adults, and made threats towards a school in Medicine Hat, Alta.

"It's important that the public remain vigilant so when they see this information out there in cyberspace and in social media that they do notify us because it allows us an opportunity to investigate the allegations," said Sgt. Stacey Kesler with the Medicine Hat Police.

In addition to uttering threats, Clapham is charged with publishing obscene material.

Police won't say whether the 18-year-old is still a student or has a criminal past.

Peter Grad, who chairs the Catholic School Board in Medicine Hat, says Clapham was enrolled in a special program a few years ago which helps kids with severe emotional or behavioral disorders.

The case has been adjourned until Thursday.