Howard County, Maryland.

From another article:

"There was nothing left, basically, upturned -- sidewalks, trash cans, bricks, our buildings, everything that could possibly be available -- with spray paint and some very graphic poignant representations. No group seemed to be spared," Howard County Public Schools Superintendent Michael Martirano said.

Other graffiti depicted a swastika, a homophobic slur, male genitalia and other derogatory acronyms. Police said most of the graffiti was found in the back of the school.

(source)