The federal police in Portland don’t even understand what ‘arrests’ are - The Washington Post

The government cannot lawfully exercise its power of arrest if it doesn’t realize it is, in fact, arresting people in the first place.
https://www.washingtonpost.com/outlook/portland-fourth-amendment-arrests/2020/07/24/c7e9822c-cceb-11ea-91f1-28aca4d833a0_story.html