There are a couple questions I have to clarify the situation.
1.) Is your friend actually "friends" with this guy, or is he just a shady dude that is hassling her randomly on campus?
2.) Has she specifically asked for your help in fixing the situation?
3.) Does he know where she lives?
I have a good friend who dealt with something along the same lines with a schizophrenic about a year ago; she lives in a different city though so I never met the guy and wasn't actively involved in the situation, I only heard about it after the fact. But I might have some insight if I understand a little more about where things stand currently.
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I know I made them a promise but those are just words, and words can get weird.
I think they made themselves perfectly clear.