Is threatening people, assaulting people, destruction of private property and placing biohazards on other people’s property also covered under your version of First Amendment protections?
Threats have to be "true threats"...ie real and immediate and to a specifically identifiable person to be actionable.
Speech is not assault.
Speech is not destruction of private property.
Speech is not placing biohazards on other people’s property.
If there are other things to charge him with, fine. Then charge him with those things. "Intimidation bias" is a violation of the first amendment.