By JOSH FRIEDMAN

Local officials placed Atascadero Middle School on lockdown Monday afternoon after a man was walking nearby brandishing a BB gun that was initially thought to be a rifle.

Shortly before 2 p.m, a 911 caller reported a man with a rifle had entered the creek behind Atascadero Middle School. Officers arrived at the scene and were told the man had approached a resident on Capistrano Avenue while carrying a weapon that looked like a rife.

The suspect then fled toward the creek, according to the Atascadero Police Department.

Officials placed Atascadero Middle School, as well as the Atascadero Unified School District office, on lockdown due to their nearby locations. 

Police established a perimeter and launched a search for the suspect. During the search, another 911 caller reported the man had brandished a rifle at children who were playing outside. 

Shortly afterwards, officers located the suspect, Arthur Castellanos, 45. Castellanos admitted to having a BB gun rifle, according to the police department.

Officers found the BB gun at the scene. Investigators later determined Castellanos was the man who had brandished a weapon at residents. 

Police arrested Castellanos and booked him in San Luis Obispo County Jail on charges of brandishing a firearm, violating probation and having an outstanding warrant. As of Tuesday morning, Castellanos is no longer in custody.