Federal agents arrested 18 during Portland protests this week

Details: These cases are being jointly investigated by the U.S. Marshals Service and Federal Protective Service, and are being prosecuted by the U.S. Attorney’s Office for the District of Oregon.

What they're saying: The protesters who've been arrested face federal charges including assaulting federal officers, arson and damaging federal property, Williams' office said.

• Earlier this week, acting Homeland Security Secretary Chad Wolf pushed back against criticism of federal agents' conduct during protests in Portland, saying, "We have been forced because of local law enforcement presence to take measures such as arrests to protect our officials."
• "We will not retreat. We will continue to take the appropriate action to protect our facilities and our law enforcement officers," Wolf added.

The big picture: Trump this week threatened to send federal law enforcement to other cities with Democratic governors, including New York City and Chicago.

• Meanwhile, Justice Department Inspector General Michael Horowitz launched an investigation into federal agents' "use of force" in Portland this week at the request of House Democrats.

Go deeper: Trump bends DHS to his will