Principle 7 - ‘Police, at all times, should maintain a relationship with the public that gives reality to the historic tradition that the police are the public and the public are the police; the police being only members of the public who are paid to give full-time attention to duties which are incumbent on every citizen in the interests of community welfare and existence.’
[0] http://www.lacp.org/2009-Articles-Main/062609-Peels9Principa...
So in Germany, you might have "Germans policing Germans", but in the US it's basically "Whites policing Blacks".
The German constitution is also very clear on this:
"Die Würde des Menschen ist unantastbar. 2Sie zu achten und zu schützen ist Verpflichtung aller staatlichen Gewalt."
https://dejure.org/gesetze/GG/1.html
"Human dignity shall be inviolable. To respect and protect it shall be the duty of all state authority."
https://www.gesetze-im-internet.de/englisch_gg/englisch_gg.h...
So human dignity is inviolable. Not "citizens", not "Germans", but "humans".