Federal agents can enforce federal law anywhere in the US. They don’t need the state’s permission to, for example, arrest someone for vandalizing a federal courthouse. What you’re referring to is federal agents enforcing state law, which is also allowed but requires registration in Oregon[1].
That’s not a defense of the current situation; we should be putting more limits on what federal agents can do (like requiring them to identify themselves during an arrest).
Yes. Federal crimes. Rioting, unless it is specifically vandalism on a federal building, is not enforceable by Federal agents, because it isn't a federal crime.
When I'll see the warrant signed by a federal judge against these people for a federal crime with probable cause, then maybe. But so far, no one was served with a warrant.
Federal officers can make warrantless arrests if they have probable cause to believe the individual has committed a crime, just like normal officers. It's hard to tell if these arrests meet that threshold, but it's at least possible that all laws are technically being following here.
Again, that's not to say this isn't a bad situation. I'm explicitly advocating for changing the laws that allow this to be even possibly legal in the first place.
In the video I’ve seen, there’s not enough context to tell whether they have probable cause. Which by the way does not require that they “just witnessed that a federal crime was committed”.
That’s not a defense of the current situation; we should be putting more limits on what federal agents can do (like requiring them to identify themselves during an arrest).
[1] https://www.lawfareblog.com/what-heck-are-federal-law-enforc...