police in usa have no legal "duty to act" :)   says-cops-had-no-duty-to-protect-su bway-hero-who-subdued-killer/ if you got a lot of lawyers and a million bucks and 10yrs to waste, and you are a "protected class".... and you can prove they "failed to act" due to your "protected status" you might get a judge to say "eh, i guess they really shoulda done something". real issue is of course due to shit like end of jim crow and immigrants we can't have fire extinguishers.
United States