Kristina Narayan, who has worked for Democratic state Rep. Tina Kotek since September 2016, according to her LinkedIn profile, was charged with one count of "Interfering with a Peace Officer."
"Kristina Narayan was arrested for Interfering with a Police Officer after the event became a riot and the crowd was given multiple orders to disperse, which she did not do," a spokesperson for the Portland police department told Fox News.
Narayan, and Kotek's office, did not respond to multiple requests for comment Wednesday.
According to the Washington Free Beacon, which first reported the news, nearly 150 calls were left on hold with Portland police Saturday as they prioritized the riot.
The Portland Police Department said that 58 other people also were arrested on charges ranging from rioting to attempted assault of a public safety officer.
"Multiple fire bombs, mortars, rocks, and other items were thrown at law enforcement during a riot Saturday night in Southeast Portland," the release said.
Videos posted on social media by Oregon Public Broadcasting reporter Sergio Olmos show police pushing through barricades set up by protesters and arresting people in their path as fireworks explode around them.
Portland police said they moved in to extinguish fires in garbage cans and on pallets of wood in the streets.
Thousands have participated in protests in Portland over the past three months since the May death of George Floyd while in the custody of Minneapolis police. The vast majority of the protests have been peaceful, but some have evolved into riots involving arson, looting and vandalism.