Merry Christmas, or whatever it is you may be celebrating, to all!
We talk a lot in this community about self-protection strategies, avoidance, de-escalation, fences, pre-emption, stun-and-run and so on. But I haven't yet heard anything about intervention to protect third parties from a crime in progress. I'm not talking about vigilantism here, simply intervening to help someone who's in danger of getting at least robbed, possibly hospitalized or killed in a criminal attack that we happen to witness.
I know this is an extremely thorny issue, and I'm sure the advice from a pure self-protection point of view would be to call the police and stay out of it. But the police aren't always close by, and we all hear stories of rapes, muggings, and even murders, where witnesses who might have been able to help walked on, stood by and did nothing or (in the worst cases) filmed the proceedings for their YouTube channel. So, as martial artists with a healthy, ethical view of violence, avoiding it when we can - what do we do? What SHOULD we do, ethically and practically? And where do we stand legally?
[This comes to mind after a recent viewing of the film 'American Sniper', where Chris Kyle's father gives his family the speech about their being three kinds of person - sheep, wolves and sheep-dogs. Essentially prey, predators and protectors. I'd guess that a number of us would like to think that, if called upon, we would be sheep-dogs. Curious about others' feelings on the subject.]