I think I'm going to fail to stop someone from assaulting another.
Why wouldn't you stop someone from assaulting another?
I think it's the easy way to find out if someone is a bad person or not.
I see your point, but it's expected of people to intervene if someone else is being assaulted. The assaulted person could really be hurt if you didn't.
I don't think it's my place to intervene, I'm gonna let it play out.
I really think you should help this person, at least call the police.