Fact check: Trump sent federal officers to cities without approval from locals
USA Today: Jonathan Entin, the David L. Brennan Professor Emeritus of Law and adjunct professor of political science, discussed how the Posse Comitatus Act of 1878 prohibits federal military from participating in domestic law enforcement, but outlined prior instances where a president has sent in federal law enforcement over the objection of state or local officials—despite the Supreme Court's assertion that the federal government lacks a general police power.
