During the Vietnam War, anti-war demonstrations were sometimes quelled through the use of billy clubs and tear gas. One notorious assault took place during the August 1968 Democratic National Convention in Chicago. Some rogue police officers took off their badges, in order to escape identification, and brutally assaulted protesters. Journalists were assaulted inside the convention hall. The actions of the police were later described as a "police riot" in the Walker Report to the U.S. National Commission on the Causes and Prevention of Violence. On May 15, 1969, police opened fire on protesters in People's Park in Berkeley, California, which resulted in serious injuries for some protesters. The 1970 Kent State shootings of 13 university students by the National Guard have been described as the culmination of such violent confrontations.