Following the arrest of a Chinese citizen for allegedly operating a drone over Vandenberg Space Force Base, the U.S. government is expanding its investigation to explore the possibility of more serious offenses. Yinpiao Zhou, 39, a lawful permanent resident, was initially charged with failing to register the aircraft and violating national defense airspace.

Court documents suggest authorities are examining whether Zhou's actions extend beyond these initial charges. While espionage accusations haven't been formally leveled, the FBI agent leading the investigation highlighted their familiarity with tactics employed by foreign adversaries to gather intelligence on military infrastructure.

Zhou's arrest occurred on December 9th as he prepared to board a flight to China. U.S. Attorney Martin Estrada emphasized the illegality of flying a drone over a military base and capturing images of its layout. According to reports, the drone flight took place on November 30th, lasting nearly an hour and reaching an altitude of almost a mile. The drone was launched from Ocean Park, a public area adjacent to the base.

A search warrant executed on Zhou's drone revealed aerial photographs of Vandenberg. Furthermore, his cellphone records indicated a Google search for "Vandenberg Space Force Base Drone Rules" approximately a month prior, along with messages discussing hacking the drone to increase its flight altitude.

This incident comes amidst a wave of reports concerning unidentified aircraft sightings across the country, some confirmed as drones while others remain unexplained. Homeland Security Secretary Alejandro Mayorkas has acknowledged these sightings, stating that some involve manned aircraft often mistaken for drones, and has denied any known foreign involvement in the northeast sightings.

With contributions from Fox News' Lee Ross.