Two days after Alex Pretti was shot and killed by federal officers during the January immigration enforcement surge in Minneapolis, David Streever was distraught. So he fired off a three-paragraph emailed rebuke to one of the officials overseeing that operation.

Five months later, that email earned Streever a knock on his door and a visit by two federal officers who issued him a stern warning and said he may have threatened Todd Lyons, then the acting director of Immigration and Customs Enforcement.

That visit prompted Streever on Monday to file a lawsuit against several Department of Homeland Security officials, claiming the officers “went to extraordinary lengths to confront and intimidate him.”

“The First Amendment unquestionably protects Streever’s criticism,” attorneys with the Foundation for Individual Rights and Expression, a nonprofit civil rights group representing Streever, said in a statement.

The Department of Homeland Security did not immediately respond to a request for comment Monday. Lyons, who left ICE in late May, also did not respond to a request for comment.