There have been threats made at schools across the country. Schools in Erie and Millcreek received threats, too.
A child was charged with terroristic threats after one was found inside McDowell High School on Millcreek this month.
Millcreek police Corporal Joe Makowski said threats against schools are not new.
He said Millcreek police will investigate school threats and bring in other agencies if needed.
There are warning signs that a student might act out and make a threat.
"Withdrawing from family activities, not hanging out or speaking with their friends as they normally would, maybe missing school or having issues at school," he said.