The only thing I can think of that the government can do is to clamp down hard on violence, including speech which advocates for violence (e.g. glorifying Luigi Mangione, calling everyone a Nazi/fascist, etc.). Freedom of speech ends where it actually turns into violence.
Reducing rights to speech that advocates for violence makes some sense, but what I'd like to see is reducing the lies and disinformation. Install a duty of candor to everyone who speaks in greatly public ways
you might have some blind spots yourself though. the biggest set of spiritual sickness and violence are whats happening to immigrants by ICE, and the support americans are giving to israel to do mass horrors to gazan civilians.
theres tons of violence going on thats much more current than talking about luigi or calling somebody who is a fascist a fascist
It's unlikely they would have killed him anonymously, from 200 yards away, and be still at large a day later.