<human>: We have this mutual friend from high school that has since entered and left the military. While in, he was diagnosed with paranoid schizophrenia.  He now lives back in our same area and just randomly shows up places, looking confused, acting erratic, scaring people.  He seems to want to cling to familiar things, old memories.  He's obsessed with my sister and has been showing up at her work, scaring customers and the other employees.

I talked with another girl he was close with before he was diagnosed and she's since cut him off, changing numbers and distancing herself from him.  She said when they talked last and he threatened her and her boyfriend.

My sister is contemplating getting a restraining order, but is afraid of exacerbating the situation.  This guys lives alone, has no known family and has nothing to lose.  

So what does she do?

Condense the text into a few key points
<bot>: Sister has a schizo stalker that she wants to get a restraining order from, but doesn't want exacerbate his paranoia into something worse.