Bovino, a nearly 30-year veteran of the U.S. Border Patrol, has emerged as a central figure in Trump's aggressive immigration strategy.

U.S. Customs and Border Patrol Commander Gregory Bovino is in federal court in Chicago, testifying before Judge Sara Ellis on alleged violations of a temporary restraining order.

U.S. Border Patrol Chief Greg Bovino will appear in federal court in Chicago on Tuesday to answer questions about his use of tear gas in Chicago neighborhoods in apparent violation of a court order.

Judge Sara L. Ellis is ordering top Border Patrol official Gregory Bovino to testify after a video showed him apparently violating her orders.

The actions would violate a federal order imposed by U.S. District Court Judge Sara L. Ellis to limit the use of nonlethal weapons and other crowd control tactics.