The Border Patrol Tactical Unit, or BORTAC, and its sister unit, Border Patrol Search, Trauma, and Rescue, or BORSTAR, were once reserved for desert rescues, executing high-risk warrants, conflicts with armed drug cartels, and manhunts. But under President Donald Trump their agents have been deployed to the streets of major US cities, putting a distinctly martial edge on the White House’s hardline immigration enforcement policies. The full force of this paramilitary surge was on open display the morning of October 25, when a convoy of BORTAC and other Border Patrol agents swept through the tranquil North Side Chicago neighborhood of Irving Park, trailed by whistle-blowing “ICE watchers” in cars and on bicycles, about an hour before a Halloween parade. It's one of several incidents in which Border Patrol's BORTAC and BORSTAR paramilitary units used force against the people of Chicago and surrounding communities in Northern Illinois during Operation Midway Blitz from last September to early November. A WIRED analysis of US government records reveals that since last year, BORTAC and BORSTAR have fronted several of the US federal government’s invasions of its own cities, often engaging in almost theatrical uses of force that litter newscasts and social feeds, adding a new salience to its self-proclaimed status as the “tip of the spear.” Audio on this video has been muted at times to comply with 's community guidelines