Ex-cop's murder trial for shooting neighbor set to start

Last September, a white police officer shot and killed an unarmed black man in his own apartment.For some, the shooting was a tragic accident with circumstances that can only be described as "very unique." Others place it in pattern of white officers killing black men that, they say, points to systemic problems in American policing.On the eve of trial, one of the only points of agreement about her case in Dallas is that it has the potential to profoundly affect the relationship between police an