No good deed goes unpunished.

BERKELEY, Calif. (AP) – A second night of protest against police killings in Missouri and New York turned violent again in Berkeley as some demonstrators threw explosives at officers, assaulted each other and shut down a freeway, police said.

Sunday’s protest began peacefully on the University of California, Berkeley campus. But as protesters marched through downtown Berkeley toward the neighboring city of Oakland, someone smashed the window of a Radio Shack. When a protester tried to stop the vandalism, he was hit with a hammer, Officer Jennifer Coats said.