SAN ANTONIO – Updated at 4:05 p.m.:
A student confessed to making the threat and was detained and transported to the Juvenile Detention Center in Seguin, Schertz police said.
Schertz police plan to review surveillance video from Samuel Clemens High School to look for clues about the person responsible for a threatening message left in a campus restroom.
Police increased their presence around the school Monday morning.
The Schertz-Cibolo-Universal City Independent School District sent an email to parents Friday and posted the information on its Facebook page about a message that had been scribbled on the wall of a girls' restroom.
The email did not include details of the threat, but police are handling the investigation and are treating it seriously.
"You just never know in this day and age," said Schertz police spokeswoman Officer Helen Lafitte. "It's just always good to have that extra presence."
Lafitte said since the school district sent out the email, her officers have been inundated with phone calls from worried parents.
"The biggest question is, 'What was the threat?' Everybody wants to know the specific threat, and at this point, we just don't feel that it's necessary to release that," she said.
What police are doing is keeping a close watch on the campus and looking at surveillance video for clues.
Seeing more uniformed officers around helped to ease the minds of some parents, like Katrina Middleton.
"My daughter wasn't too concerned. I am extremely concerned, of course," Middleton said. "I knew that there would be increased police presence, and it is nice to see that they're out here."
Clemens High School student Kyla High said she somehow missed the message.
Hearing the news was surprising but not especially unsettling for her.
"Just a little," High said. "Some people would probably look at it as a joke, but it could be serious."
That's exactly how police feel about the issue.
They said it's just a matter of time before they know who is responsible for the threat and they plan to pursue criminal charges against that person.