ARLINGTON, Texas (AP) — A police officer who killed an unarmed college football player during a suspected burglary at a Texas car dealership was fired Tuesday for making mistakes that the city's police chief said caused a deadly confrontation that put him and other officers in danger.Arlington officer Brad Miller, 49, could also face criminal charges once police complete their investigation, Police Chief Will Johnson said.Called to the scene of a suspected burglary early Friday morning, Miller pursued 19-year-old Christian Taylor through the broken glass doors of a car dealership showroom without telling his supervising officer, Johnson said.Instead of helping to set up a perimeter around the showroom, Miller confronted Taylor and ordered him to get down on the ground, Johnson said.