A Colorado district attorney charged a federal immigration officer with third-degree assault and criminal mischief on Tuesday in a move the Department of Homeland Security called "unlawful" and a "political stunt."Eric P. Murray, the district attorney for Colorado's 6th District, announced Tuesday he's charging U.S. Customs and Border Protection Officer Nicholas Rice with the two counts for an incident that occurred during an immigration enforcement activity in Durango, Colo., between Oct. 2728.Anne Francesca Stagi told investigators that Rice knocked her phone out of her hand while she was protesting outside a U.S. Immigration and Customs Enforcement facility in Durango, according to The Associated Press.Video of the incident shows Stagi holding her phone in front of a masked immigration agent's face before the agent grabs it.DOJ SILENT ON WHETHER NYC POLITICIAN WHO ALLEGEDLY ASSAULTED ICE OFFICER WILL FACE CHARGESStagi then appears to grab the officer's shoulder as he walks away at which point he grabs her and, along with other federal agents, brings her to the ground, the video shows.Stagi claimed that the officer put her in a chokehold and that she still feels pain when she puts on a jacket.The prosecution comes after the Colorado Bureau of Investigations (CBI) opened a probe into the incident at the behest of Durango Police Department Chief Brice Current, according to the AP.DHS claimed that the prosecution was a political stunt and that states have no authority to investigate cases of this nature. "Federal officers acting in the course of their duties can only be investigated by other Federal agencies," DHS told the AP in a statement.ILLEGAL IMMIGRANT SUSPECTED OF GANG TIES ARRESTED AFTER ALLEGEDLY RAMMING ICE OFFICERThe agency is still investigating the case, per the AP.Fox News Digital contacted DHS, CBP, Colorado's 6th district, CBI and the Durango Police Department for comment but did not immediately receive a response.The Associated Press contributed to this report.