It should not have to take the NYPD to know that short skirts and immodest dress in general are an invitation to trouble. Our forefathers in this land knew better than to dress like drunken heathen. And its not just an Islamic thing. People can find in their Bibles condemnation of immodesty in clothing.
My point is, the way people dress change. What is considered 'modest' change. Men wearing T-shirt would be considered inappropriate in the past, since T-shirt was considered underwear. Today, women wearing short skirt has been accepted as appropriate dress, at least in New York.