That's one end of the spectrum of violence.
What about the other end? Should you go to jail if you don't report that your son/daughter/wife/mother is on Facebook talking to people you aren't too sure about?
Trump's statement makes it clear you'd go to jail for that. Not just for failure to report someone about to commit a crime.
Had he limited his statement to just that... it'd be fine. But he didn't. And couple that with his authoritarian nature... and this will be our Stasi.
Accessory Before The Fact
Definition
A person who aids, abets, or encourages another to commit a crime but who is not present at the scene. An accessory before the fact, like an accomplice, may be held criminally liable to the same extent as the principal. Many jurisdictions refer to an accessory before the fact as an accomplice.
Illustrative case law
See, e.g. Standefer v. U.S., 447 U.S. 10 (1980)
