A former United States Marine posed as a security team member for Marine One, the helicopter that transports President Trump, and breached two checkpoints last week at Palm Beach International Airport, the authorities said.

The former Marine, Brandon M. Magnan, 37, of Naples, Fla., was charged on Jan. 6 with false personation of officer or employee of the United States, according to a criminal complaint by the United States Secret Service.

It wasn’t clear why Mr. Magnan was trying to get near the helicopter. Marine One, which is piloted and protected by the Marine Corps unit known as HMX-1, is used to transport the president for shorter trips, the Secret Service said.

Mr. Trump was spending his winter vacation in Palm Beach, Fla., at his private Mar-a-Lago resort at the time of the episode with Mr. Magnan.