Federal immigration officers have shot 11 people since September as the Department of Homeland Security has ramped up deportation operations around the country. In the majority of the shootings, officers have fired into cars — a tactic that law enforcement authorities and policing experts have been trying for decades to curtail. The vehicle shootings raise serious concerns among policing experts about the rapidly expanding deployment of DHS personnel into American communities, where officers are regularly captured on video clashing with immigrants who are in the country illegally as well as citizens who protest the arrests. The shootings “are not one-offs,”...