Military Surveillance Planes Didn’t Spy on Protesters, Pentagon Report Finds

WASHINGTON — Deploying a little-known National Guard reconnaissance plane in four American cities to monitor protests this spring did not violate rules against the military collecting intelligence on citizens, a Pentagon report has concluded.

But the report by the Air Force inspector general found that National Guard officials failed to obtain prior approval from Defense Secretary Mark T. Esper to use the planes because they mistakenly believed they were not intelligence aircraft, which require high-level signoff.

The inquiry was prompted by lawmakers who expressed concerns to Pentagon officials that the use of the aircraft, RC-26B surveillance planes, in late May and early June may have violated the civil liberties of the mostly peaceful protesters demonstrating against police brutality and systemic racism.

Mr. Esper responded by ordering an investigation, which was conducted by Lt. Gen. Sami D. Said, the Air Force inspector general. The Air Force’s action came after the Pentagon’s top intelligence policy official told Congress that the nation’s military intelligence agencies did not spy on American protesters during the wave of nationwide demonstrations.