They allege a multiracial group of three or four young males were in a car on Sunday evening after dark and mugged someone near the Mollie Stone's store at the corner of 18th Street and Collingwood.
The group then drove up to Collingwood and 19th Street, near where the Harvey Milk Civil Rights Academy.
A few of the males got out of the car and tagged four spaces - a utility pole, a tree, a sidewalk and the side of a private residence - with jet-black paint, in the section of 19th Street between Collingwood and Castro. It does not appear that the graffiti was anti-gay.
On Monday morning, neighbors and business owners awoke to the tagging blighting the area, began to clean up the mess and the San Francisco police were alerted to the problem. An officer was dispatched to investigate but I don't know if a report was made.
When I get more info, I write a new post.