Examples law enforcement in German examples

How do I translate law enforcement into German?

Movie subtitles

What was expected to be a peaceful demonstration amongst residents and law enforcement turned deadly when what was believed to be a home-grown militia opened fire.

Was als friedliche Demo von Anwohnern und Polizei geplant war, schlug in Gewalt um, als Angehörige einer Miliz das Feuer eröffneten.