We have no idea who did this yet -- but no matter WHO it actually is, they will decide it's the "radical left."
The one thing I'm very sure of is that this person was a trained sniper of some variety.
Outside of that, they're going to use this man's death to forward their own agenda and they don't care what the actual story is, because they are going to try to wring every drop of influence out of Charlie Kirk that they can, making how he died more important than his death, and they will try to convince everyone that it's grief, not opportunism.