Racist violence against has marred American society since the colonial period, beginning with the treatment of Native Americans and then African-Americans. The violence directed against minority groups by both law enforcement and private citizens has included beatings, lynchings, and, today, shootings of unarmed black people by police officers and in some cases private citizens. In recent years, a number of high-profile killings have prompted heated public debate, a number of criminal cases, and the rise of activist groups such as Black Lives Matter. Police killings raise important ethical as well as legal and political issues related to the common good, including the use of profiling, the responsibilities of police officers, the meaning and value of public order, gun control, and implicit bias.