...dunno who is responsible for this. It could be blm or antifa or the proud boys or anyone else. Regardless, they need to be found, arrested, tried, convicted and sentenced to at the very least life in prison without parole. No matter which political side you fall on, blowing folks up to get your way politically is terrorism and should be treated as such.
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!