Edited later to add:

The original press release seems to be gone now, but here is what is claimed to be the revised release, and an article on the same topic.

https://www1.wdr.de/nachrichten/polizei-dortmund-greta-gewaltbereit-100.html

https://www.yahoo.com/news/german-politician-calls-greta-thunberg-102611513.html