answer: #Person1# asks #Person2# the questions about an illegal departure.
documents: #Person1#: What should you do if you find out a man may has an illegal departure in exit control point?
  #Person2#: We can inform the department in charge and ask for revocation of passport.
  #Person1#: What else do you need to keep him in temporary custody?
  #Person2#: We need a detention warrant.