A Minnesota prosecutor has announced an investigation into federal immigration officers, including Border Patrol official Greg Bovino, who was a key figure in the Trump administration's immigration enforcement operations. The Hennepin County Attorney Mary Moriarty's office is already investigating 17 cases, including one where Bovinos threw a smoke canister at protesters and another where federal officers used chemical irritants during an arrest outside a high school. The Department of Homeland Security, which oversees Border Patrol, and the Immigration Department, did not immediately respond to a request for comment. The investigation will only focus on incidents in Minneapolis-St. Paul, which was followed by nationwide demonstrations and criticisms of DHS use-of-force policies.