Parents and students in Valley Stream saw more police patrols at their schools after a threat was made on social media.

Police say special units were deployed.

Students were also told to leave all bags at home and North and South high school students also remained in the building for lunch periods.

This threat comes after a 13-year-old student was arrested for threatening to shoot up Copiague Middle School Monday.

There was also another threat that some say led to the evacuation of Copiague High School.

News 12 spoke with Denis Monette, a counterterrorism expert and former Nassau assistant police commissioner, about the recent wave of threats.

"They have to do the outreach right away and not wait until the next one happens. They have to come right out and say we're having an assembly," says Monette. 

Monette also tells News 12 it's important for schools to be transparent with their students about the severity of the situation.