Graffiti threat leads to increased police presence at Walnut Creek's Las Lomas High School

WALNUT CREEK, Calif. (KGO) -- A Walnut Creek high school added extra police officers Tuesday because of a graffiti threat.

It was found scrawled inside a boy's locker room at Las Lomas High School.

Police conducted a risk assessment and determined the campus was safe.

Officials decided to keep the school open, but assign more plainclothes and uniformed police officers to the campus.

Officers and school administrators decided not to cancel classes Tuesday and instead increased the number of both plain clothed and uniformed police officers.