CANOGA PARK ( — Police arrested a suspect Thursday believed to have dumped a loaded gun across from Canoga Park High School and fled onto the school’s campus, triggering a three-hour lockdown.

The suspect, described by police as a 19 or 20-year-old man who is not a student, was reportedly seen acting suspiciously in front of a Taco Bell across from the high school. A school employee alerted campus police.

When campus police approached the suspect, he reportedly dumped a loaded gun in the trash and fled across traffic on Topanga Canyon Boulevard, scaling the fence and disappearing onto the high school campus.

Campus police and LAPD officers swarmed the campus, placing it on lockdown. Students and teachers remained in their classrooms for over three hours.

The suspect was able to elude police during the lockdown. Only after students were permitted to leave did officers reportedly look in other areas and spot the man. He was arrested without incident.

Police recovered the weapon believed to have been discarded by the suspect. He had no other weapons in his possession at the time of the arrest.

Authorities are describing the incident as a successful example of “if you see something, say something” in action.