California became the first state to ban most law enforcement officers, including federal immigration agents, from covering their faces while conducting official business under a bill that was signed Saturday by Gov. (AP Photo/Ethan Swope)California became the first state to ban most law enforcement officers, including federal immigration agents, from covering their faces while conducting official business under a bill that was signed Saturday by Gov. The ban is a direct response to recent immigration raids in Los Angeles, where federal agents wore masks while making mass arrests. Proponents of the California law said it is especially needed after the Supreme Court ruled this month that the Trump administration can resume its sweeping immigration operations in Los Angeles. The law aims to boost public trust in law enforcement and stop people from impersonating officers to commit crimes, supporters said.