FBI agents arrested a woman accused of surveilling Taiwan’s president’s son in Seattle as she tried to board a flight to China at Los Angeles International Airport.

Wanying “Heather” Zhang, 34, was taken into custody Sunday and was expected to appear in federal court Monday. Court documents allege she watched the president’s son in Seattle last year. Federal prosecutors say the activity was part of unauthorized intelligence gathering in the United States.

A criminal complaint alleges Zhang worked with an associate to photograph and record the president’s family outside their Seattle-area home. She also reportedly sent photos, videos and the son’s license plate information at the direction of Chinese officials. The allegations have not been resolved in court.