“Jason Van Dyke, a white Chicago police officer, was found guilty of second-degree murder on Friday, nearly four years after he shot and killed Laquan McDonald, a black 17-year-old holding a knife. The closely watched trial highlighted the fraught relationship between this city’s police force and its residents, particularly people of color, as well as questions about how officers use deadly force. Van Dyke is scheduled to appear in court on Oct. 31 for sentencing.”