Rumor on twitter is that this was a rendition of a government informant back into safety.
True or not, a variation on this tactic needs to be used frequently:
“Johnny Smith was arrested for setting fire to the Portland Federal Building. But thanks to the information he has provided us, we are now poised to indict thirty-five senior ANTIFA leaders over the next few weeks. Johnny is a hero, and we here at the DHS thank him for his service to the nation.”
Then let him go on the streets of Portland. ANTIFA will soon find itself very short on loyalists. :)