When I spoke about officers not identifying themselves I was talking generally, about the other cases from outside of portland, of officers obscuring their badges and not identifying themselves.
But no, that's not really what I would count as secret police. I mean I think the distinction is a little arbitrary and before long you basically get to arguing definitions which is almost always a waste of time, but I think the actions of the police in the snopes article constitute an overstep that I think qualifies as authoritarian. Especially when those agencies were sent in specifically by the executive.
Also, I should point out that the line you quoted is the one I have a problem with:
> we have no verifiable evidence to prove or disprove whether agents in those cases explained for what federal agency they worked during the arrests.
That's a very strange sentence to me: like how could you even prove such a thing? Have a video of the entirety of the person's interaction with the police?
I think if we're being reasonable here that it's overwhelmingly likely the police didn't identify themselves in this case. But of course it's not feasible to have "evidence" for that kind of thing, so I suppose I can't go ahead and say I'm sure on the point.