Angeles also led to nationwide rioting with similar mass deaths. During the same time period, and since then, numerous violent acts committed against African-American churches have been reported. Modern era (1972–present) Today racial violence has changed dramatically, because openly violent acts of racism are less prevalent, but acts of police brutality and the mass incarceration of racial minorities are continuing to be major issues within the United States. The War on Drugs has been noted as a direct cause of the dramatic increase in the number of incarcerations in the nation's prison system, which has risen from 300,000 in 1980 to more than 2,000,000 in 2000, though it does not account for the disproportionately high African American homicide and crime rates, which peaked before the War on Drugs began. During the 1980s and '90s a number of riots occurred that were related to longstanding racial tensions between police and minority communities. The 1980 Miami riots were catalyzed by the killing of an African-American motorist by four white Miami-Dade Police officers. They were subsequently acquitted on charges of manslaughter and evidence tampering. Similarly, the six-day 1992 Los Angeles riots erupted after the acquittal of four white LAPD officers who had been filmed beating Rodney King, an African-American motorist. Khalil Gibran Muhammad, the Director of the Harlem-based Schomburg Center for Research in Black Culture has identified more than 100 instances of mass racial violence in the United States since 1935 and has noted that almost every instance was precipitated by a police incident. The Cincinnati riots of 2001 were caused by the killing of 19-year-old African-American Timothy Thomas by white police officer Stephen Roach, who was subsequently acquitted on charges of negligent homicide. The 2014 Ferguson unrest occurred against a backdrop of racial tension between police and the Black community of Ferguson, Missouri in the wake of the police shooting of Michael Brown; similar incidents elsewhere such as the killing of Trayvon Martin sparked smaller and isolated protests. According to the Associated Press' annual poll of United States news directors and editors, the top news story of 2014 was police killings of unarmed Black people, including Brown, as well as the investigations and the protests afterward. During the 2017 Unite the Right rally, an attendee drove his car into a crowd of people protesting the rally, killing 32-year-old Heather D. Heyer and injuring 19 others, and was indicted on federal hate crime