NORTH TEXAS (CBSDFW.COM) – Today several schools across North Texas are increasing security after threats of violence. The possession of weapons and threats made against students and teachers here all happened just one day after a deadly mass shooting at a school in Florida.

Threats were made to the Kaufman, Community and Arlington Independent School Districts. The student in Arlington, a 13-year-old, was arrested for saying he planned on taking a gun to Nichols Junior High School.

On Thursday guns were found on the campuses of South Garland High School, Flower Mound’s Marcus High and Plano West Senior High.

The incident in Plano involved a male 16-year-old who was taken into custody after it was learned he brought a handgun to campus.

In Flower Mound another 16-year-old was caught with a gun. Police say that student, who was also arrested, had a full magazine.

Student Dominique Beachum said, “People had seen it, a kid had showed it off. People knew that he had it. Once one student knows, every student knows.”

Some adults were not only concerned about the gun found at Marcus but how the situation was handled. “I’m sorry, we should have been notified immediately,” said parent Terri White. “School should have been put in lockdown immediately [and] it wasn’t. Policy was not followed. That upsets me.”

A small, unloaded handgun was found in the backpack of a South Garland H.S. student. School resource officers were actually searching the backpack of 19-year-old Kerry Guery because another student claimed Guery had stolen a cell phone. As police went through his bag they found the missing phone, the gun and a small amount of marijuana. Guery is now facing a number of charges.

No students, faculty or staff were injured at any of the schools where guns were found or threats were made. Police in each city are said to be still investigating as to why the students brought firearms to campus.