OVERLAND PARK, Kan. (AP) — Authorities say a 19-year-old man has been arrested after two students attending a Kansas summer program said he threatened them.

John Douglass, who heads emergency services for the Shawnee Mission School District in suburban Kansas City, told KMBC-TV two students received threats Wednesday and notified security. That triggered an emergency response that sent out alerts to district officers, along with a photo of the suspect.

The school was locked down with about 600 summer school students.

Surveillance cameras then captured images of the man walking around the school. Douglass says the man, a 2014 graduate of the school, was arrested nearby.

Douglass says police later found rifles and shotguns “piled against his bed” at the home where the man was staying.

No formal charges had been filed.