This is consistent in the majority of mass shootings in the past couple of years.
You look a little closer at what didn't get printed, you find again and again that the facts were whittled down and nearly all the conflicting information was shaved off before officials settled on an explanation.
Why do they do this? Well, the cops on the scene are lazy as hell. They want to do the minimum amount of work they can possibly get away with. This is why they appreciate "narrators" with Federal authority who show up and "explain" to them what happened, complete with corroborating anecdotes. This allows the police to go back to doing what they excel at, which is staring through a glass cabinet at Krispy Kreme trying to decide on what donut they want. They are after all, merely human beings and as a rule the majority of human beings are unbelievably incompetent at their jobs. The police are no different from lawyers, teachers, soldiers and doctors in the modern era. They're lazy and they avoid situations which cause pain, like crime scenes that present a lot of confusing evidence that might require them to do a lot of work to untangle the facts and figure out what actually happened.