Last weekend added another chapter in the history of racial terrorism against Black people in America. Payton Gendron, 18, drove three hours from his home in Conklin, N.Y. (south of Binghamton) to a Tops Friendly Market in the majority Black neighborhood of East Buffalo and shot and killed 10 people and wounded three. The ten victims—Robert Drury, Margus Morrison, Andre Mackneil, Aaron Salter, Geraldine Talley, Celestine Chaney, Heyward Patterson, Katherine Massey, Pearl Young and Ruth Whitfield—ranged from 32 to 86 years old. The three wounded—Zaire Goodman, Jennifer Warrington and Christopher Braden—are between ages 20 and 55. Salter, a former police...