rule # 1 -- put it in writing. No legitimate LL does business on verbals and turns over keys and possession to a stranger,...on a ''chat''.
if indeed you feel your research indicated your LL might be a problem and you are concerned for your safety, you could wait till something happens or just get your stuff out of the room and disappear, forfeiting your security deposit for the lesson learned. LL will probably not pursue you for a four month term on a verbal, against the security deposit you forfeit. don't trash the place,...take pictures of condition, send keys back cert mail with a proper note with a copy of note posted on room door.