JMO, but for me the line is
when I see them doing something illegal. There are plenty of "loners" or "oddballs" out there who are harmless. In NK's case, when that line got crossed over, LE
was aware of it, charges were filed, etc.
I mean, if I were going to report someone to LE simply because I and more than a few others thought they were crazy (ie. displaying personality-disordered or paranoid thinking and actions), well, I can think of 2-3 family members by marriage who pop up immediately...
ETA: and also JMO, I don't believe one is morally culpable for not reporting a person who has ever displayed "off" behavior. That person has a chance of going on to choose to do good instead of bad, too, especially if things start going in a positive direction for him; you can't be responsible for any choice he
might do. Are you equally responsible for the kid down the street who ends up being an Eagle Scout?
IMO, Gladys Kravitz 2 doors down probably wouldn't help two already disadvantaged kids with that nudge in the right direction (especially if still young and somewhat impressionable). Mean that in the best way (loved that character
).