Passage: That evening, a mysterious woman arrives at Sarah's door, asking to use the telephone to call for help. Sarah lies that her husband is sleeping and she does not want to be disturbed, but the woman tells her that she knows that he is dead. When the visitor persists on coming in, Sarah, a professional photographer, attempts to take her photo through a window and telephones the police.  When they arrive, the woman has already vanished. The police assure Sarah that she will be fine, but arrange to have a patrol car visit throughout the night.

Question: what actions do the police take to protect Sarah?
patrol car visit throughout the night