The vast majority of demonstrations over the George Zimmerman verdict have been peaceful, but on Monday night, protesters clashed with police in Los Angeles. After several hundred people gathered for a “prayer rally” in Leimert Park, about 100 to 150 broke off and started smashing windows, jumping on cars, and blocking traffic on Interstate 10, according to the Associated Press. Mayor Eric Garcetti, who cut short a trip to the East Coast, tweeted, “We should respect Martin family’s call for peace. Unlawful assembly declared. Police are clearing area.” By the end of the night, thirteen people had been arrested for vandalism and assault. LAPD Chief Charlie Beck said police will be stricter with protesters in the coming days. “This will not be allowed to continue,” Beck said.