A federal judge on Wednesday dismissed assault charges against a manager of the Laugh Factory comedy club in Chicago stemming from a confrontation with Border Patrol agents in Lakeview, after federal prosecutors revealed a grand jury refused to indict him.

Last week, without explanation, federal prosecutors filed a motion to dismiss all charges against Chicago Laugh Factory manager Nathan Griffin, who had been charged with forcibly assaulting, impeding, and interfering with a federal officer.

Prosecutors did not explain the reason for dropping the charges in their filing last week, but at a hearing before U.S. Magistrate Judge Keri Holleb Hotaling on Wednesday, they revealed a grand jury had returned a "no bill" in Griffin's case, refusing to indict him.

Federal authorities had accused Griffin of assaulting a U.S. Customs and Border Protection agent outside the Lakeview comedy club in October.

Griffin was accused of forcibly closing a door on a Border Patrol agent's leg as agents were searching for a body-worn camera they believed had been dropped near Broadway and Belmont Avenue during a previous immigration-related arrest.

The agent suffered "a small gouge and scrapes on his right leg" when Griffin closed the door on his leg, according to the charges against Griffin.

Video posted on the club's Instagram page shows agents wrestling Griffin to the ground as a Chicago police officer stepped in to separate a bystander from the scuffle. Other bystanders could be heard screaming for help and insisting, "He didn't do anything!"

Once handcuffed, Griffin was put in the back of the white van as the bystanders repeatedly asked, "Where are you taking him?"

Prosecutors' decision to drop the case against Griffin is just the latest such move involving various arrests from the Trump administration's immigration crackdown in the Chicago area.

Last month, federal prosecutors dropped charges against Marimar Martinez, a woman who was shot by a Border Patrol agent in Brighton Park, after federal authorities accused her of ramming an agent's vehicle.

In Martinez's case, a spokesperson for the U.S. Attorney's office in Chicago said prosecutors are "constantly evaluating new facts and information relating to cases and investigations arising out of Operation Midway Blitz, the largest ever law enforcement surge in the Northern District of Illinois."

"This continuous review process applies to all matters—whether charged or under investigation. It helps ensure that the interests of justice are served in each and every case, and that those cases that are charged are appropriately adjudicated through our federal court system," he added.

The same day as Martinez's case was dismissed, also dismissed charges against 70-year-old U.S. Air Force veteran Dana Briggs, who was arrested in September during protests in Broadview.

He was accused of making contact with a federal agent while handing his cell phone to another protester as he was taken into custody for ignoring orders to clear the street.

He was initially charged with felony assaulting or resisting federal agents, but the charges were downgraded to a misdemeanor in October. All charges against him have now been dropped.

Four other people were arrested on the same September day that Dana Briggs was booked at the Broadview ICE facility. All of their charges were also dropped.