An Immigration and Customs Enforcement agent pleaded guilty to a misdemeanor battery charge on Wednesday for throwing an activist to the ground near Chicago last year during the Trump administration’s immigration crackdown in the region.

A judge in Cook County, Ill., sentenced the agent, Adam Saracco, to 12 months of supervision on Wednesday and ordered him not to have contact with the activist he had clashed with, Robert Held.

Mr. Saracco, 41, was charged with misdemeanor battery earlier this year after the altercation in December. At a gas station in Brookfield, Ill., Mr. Held was filming Mr. Saracco when Mr. Saracco approached him. Mr. Saracco took Mr. Held’s phone and threw him to the ground. Mr. Saracco was off duty at the time and was getting gas after leaving a nearby immigration detention center. Mr. Held said he did not sustain any injuries.

It was not clear whether Mr. Saracco was still employed by ICE. The Department of Homeland Security said in a statement on Wednesday that the agency “does not comment on personnel decisions.” Mr. Saracco did not respond to a request for comment.

Mr. Held, a trust and estate lawyer, joined many Illinois residents in protesting against ICE last fall amid a surge in immigration arrests across the Chicago area, which the Trump administration called Operation Midway Blitz.

“I am pleased that there is some accountability,” Mr. Held, 68, said in an interview on Wednesday. He added that he remained “deeply troubled and concerned” by the actions of federal agents.

“This resolution represents an important step for accountability and shows that Cook County will not turn a blind eye to unlawful conduct, no matter who you are,” Eileen O’Neill Burke, the state’s attorney for Cook County, said in a statement on Wednesday.

Ms. Burke said that her office would seek justice on behalf of those harmed during the Trump administration’s crackdown in the Chicago area “when the evidence and the law allow us to prosecute.” There have been very few local prosecutions of immigration agents.