The park Service said that the violence started when Trump violently dispersed the crowd. 6:30 PM
The part about projectiles including bricks, frozen water bottles and caustic liquids being thrown, and the caches of glass bottles, baseball bats and metal poles hidden along the street seems to have escaped your limited attention. Not to mention that Intelligence had revealed calls for violence against the police. Try to connect the dots. This may be difficult for you to understand, most things are.
These are the truths you ignore.