Police translates as "משטרה.
The word "שוטר" translates as policeman, police officer, or "cop".
The first is a collective noun, where the second refers to an individual. "Police" is just not a correct translation of "שוטרים".
I would say that in this case the group of people who speak of themselves, are definite: אָ֫נוּ בְּנֵי־הָאָדָם יְצוּרִים מְאוּסִים we human beings are wretched creatures. In the same way it would be: אֲנַ֫חְנוּ הַשּׁוֹטְרִים יְעִילִים