...could be one or more holdouts hanging the jury up. Could be some who believe the political narrative on this and don't want to be confused by the facts.
...what the left really fears is that an ordinary citizen might stand up and do what the cops should have been doing all along. It could set a dangerous trend and the left is not famous for burning down businesses that are willing and able to fight back.
...my old dad told me back in the sixties when they were having all the riots that it could not go on that way without the cops. His contention was that the cops were there mostly to protect the rioters from their victims. Were it not for the cops, the public would take care of itself.

Liberals are like a "Slinky". Totally useless, but somehow ya can't help but smile when you see one tumble down a flight of stairs!