It's the video.

It was always a story, fairly high up, but it wasn't THE story until the video dropped. The fact that they fired and went after the cops FAST got a lot of attention. Then the police, feds, and family asking people to remain calm and not riot 24 hours before release meant it was going to be bad.

Now it's going to be a dragged out legal process, which is much less easy to push compared to a 10 minute execution.