A white Chicago officer was convicted of second-degree murder Friday in the 2014 shooting of a black teenager that was captured on shocking dashcam video that showed him crumpling to the ground in a hail of 16 bullets as he walked away from police. The video, some of the most graphic police footage to emerge in years, stoked outrage nationwide and put the nation’s third-largest city at the center of the debate about police misconduct and use of force. The shooting also led to a federal inquiry and calls to reform the Chicago Police Department. Jason Van Dyke, 40, was...