“Officers exercising their official duties, particularly in public, do not have a reasonable expectation of privacy.”
Nine federal appellate circuits have found a First Amendment right to record police, ICE and CBP doing their jobs in public. Wiretap laws do not reach audio here, because an on-duty officer has no privacy expectation to violate. The operational half of this guide matters more than the legal half. Use a strong passphrase and turn biometric unlock off, since searching your phone takes a warrant and taking your thumb does not.