Radio Diary: A Harvard Law Professor Explains Why Federal Officers' Tactics In Portland Are Unlawful

Unidentified federal officers in Portland  — and soon, in Chicago and Albuquerque —have been arresting and detaining protesters in unmarked vehicles, sometimes far away from the federal buildings they're purportedly there to protect.

In one notable instance, two federal officers grabbed a man off the sidewalk and, without identifying themselves or giving a reason, put him in an unmarked van and drove off to question him.

The Department of Homeland Security claims the officers' tactics here are lawful. Harvard Law professor Andrew Manuel Crespo says they are decidedly not.

"The person in charge of this newly beefed-up, paramilitary federal police force doesn't know what an arrest is," he says of Federal Protective Services Deputy Director Chris Cline. "It means he doesn't know when they're violating the fourth amendment — like they unquestionably did."

Listen to Professor Crespo explain why the officers' conduct is unconstitutional — and why he finds it frightening that authorities seem to think otherwise.