It has been established multiple times that police has no duty to protect, except for the situations where the police actions put a person in a harm's way. There were several cases affirming that. A cop arrested a husband driver and left his wife stranded and she was raped; another cop alerted a violent man that the neighbors complained about him and he slaughtered them when the cop left; another cop took a motorist's keys away in the middle of a snowstorm and the motorist froze to death; in all those cases the court decided that the cops were liable despite the general lack of duty to protect.
Now, suppose a city enacts an ordinance precluding weapon carry. A licensed gun owner is thus prevented from carrying a gun for protection. She gets assaulted because she wasn't able to protect herself without a weapon. Does the gun control ordinance make the city liable for failing to protect her because said ordinance put her in a harm's way?